ZS 180 bits - The Car
February 2014: No further problems with exhaust mountings, but other work needed. The original insurance company had no qualms about the modified exhaust, but renewing online elsewhere for a £100 saving there were no questions on the form but perusing the documentation subsequently I noticed a statement about modifications that was pre-filled with 'None'. Rang the company and told them, and they wanted to know how much BHP it added. I said I didn't know, and they suggested I ring the previous owner! I told them I'd had the car six years, and they asked what previous insurance companies had done about it. I told them they had been fine with it, but they insisted on knowing the BHP. I couldn't find out what make it was, and vendors of other after-market systems wouldn't say, saying it depended on all sorts of factors including fuel grade, and even the weather! I made some enquiries about putting it on a rolling road, at about £80, but had no guarantee the insurance company would accept that. It's going to be easier just to replace the back box with the original. Get under the car to start that, and find the nuts between middle and back sections heavily corroded so will need cutting off. Also whereas the original back box has welded studs facing forwards, the middle section appears to have studs facing backwards! And going by the nuts the studs would be equally as bad, so I'd have to cut them off and drill them out, and use nuts and bolts. So maybe it had been a 'cat back' enhancement i.e. both middle and back sections. Another factor is that been aware of a slight blow near the middle of the car for a while, and I found a very small hole in the centre box. No point in swapping the back box without replacing the centre section. But as the weather has been lousy lately, and it would need the ZS up on the ramp i.e. the two MGBs outside, I decided to have someone else do it.
Halfords quoted me £120, I could have got it cheaper at Sh*tFit but wouldn't trust them not to wreck the very expensive cat section, so had it done at Halfords, including swapping the rear boxes. I had the after-market rear box back, with a view to eBay-ing it, but the flange was so heavily corroded even though the rest of the system was pretty-well pristine stainless, I just junked it.
I investigated various options - companies large and small, as well as DIY kits, also scanned forum posts. Now the summer is upon us (in season if not weather) companies that were charging £25 or so in winter are charging £49 or more. DIY kits just add more fluid, but by the time you have bought a bottle plus the gauge and connector you are talking about the same money. The other problem with those is that they don't check for leaks, don't add leak detection fluid, and they don't add fluid by weight which is what you are supposed to do, and adding fluid to a pressure reading you can end up with too much or nowhere near enough. So I opted for a local mobile specialist - Roadchill at £20 for a system check and £20 for a recharge if all was good.
First thing was to check the pressure which with A/C off was near normal, although way down with A/C on. Next was to extract the remaining fluid - 140 gm left, so no major leaks. Next evacuate the system as another leak check, then add leak detector for any future problems as well as lubricant. Finally add new fluid by weight - 560 gm. Before the work face-vent temp was 23C, after 6C. Very happy with the job, I can recommend Roadchill.
Battery Added May 2009
The ZS tends to stand for a week quite often, longer in the summer when we use the V8 for pottering around. I'd been aware that the battery had been getting a bit soft for a while, but it didn't fail to start the car until this week. As that was just under a week after I had driven the car for an hour or more, and the starter was really whizzing the engine over the day after that, it's time for a replacement. As it was an MG/Rover battery, presumably the original, 4 1/2 years or so isn't bad I suppose. As luck would have it I had a sheet of discount vouchers for National Tyres and Autocare including £10 off batteries. Did some research and Halfords have a 5-year HCB075 with 60Ah at the 20-hour rate and 540 'starting' amps at £85, whereas the original states 63Ah and 570CCA. They also have a 4-year HB075 at £75. National Tyres have a 5-year GTE 075 with 600 'Voltage charge' (presumably CCA!) at £82 and a 4-year version with 540 at £72 so slightly cheaper than Halfords. You also get an 8% discount for ordering on-line from National (specifying the fitting station you want to use, then they tell you when it is in stock), although with my voucher I was able to do even better than that. Straight-forward dropping the new battery in, at the cost of losing the radio tuning and clock time.
Update February 2014: Although I added the cut-off switch in 2009 I generally only use it in the summer when the car could go for several weeks without being used in the better weather. Normally in the winter it got regular runs of 80 miles or so. However this winter for various reasons it's only doing a few miles per week, and I've noticed the cranking speed gradually getting slower, much as it did in 2009. I didn't want to pay-out for a new battery after just five years, when the two MGBs are lasting double that, so I thought I'd try a boost charge. It's always been the case that vehicle charging systems won't put back the full charge if the battery has been significantly discharged, as they are limited to 14.5v or less. These batteries are designed to give a high current for a short period of cranking, not to be noticeably discharged then recharged, unlike 'leisure' batteries for caravans and motor homes. However boost charging - within limits - will restore a battery capacity. So I took the battery off (not without some trauma) and recharged it on the bench with my high power charger. Initially it took just under 6 amps and registered only 13v, but after about five hours it had dropped to 4 amps and registered about 15.5v (on charge, dropped rapidly to just over 13v off-charge). Refitted it, check the car started, then left it overnight with the cut-off switch not turned off. Next morning cranking was significantly faster than previously, and that was after a night of alarm and ECU discharge. Ditto after two more days of not being turned off, and journeys of just a few miles, so the capacity restoration ploy seems to have worked. I shall have to use the cut-off switch as a matter of course from now on.
Battery Clamp Problems: Incidentally the trauma in removing the battery was that initially the clamp bolt was quite stiff, then came free with a 'ping'. However nothing so convenient as shearing the clamp bolt, the welded nut under the battery box had broken free, trapping the battery. And of course the battery box fixing bolts are under the battery. However with a strip of metal to protect the battery case I was able to use a large screwdriver to lever the clamping flange on the other side back just enough to get the battery out, which enabled me to remove the battery box and re-weld the nut. This time along all four sides of the (square) nut, rather than tack-welds at each corner. All refitted with copper-grease, and another example of checking you can undo things before you have to, instead of waiting until you need to, find you can't, and are stranded.
Update July 2009: Not long after writing this section I came across this Battery Brain which automatically disconnects the battery if it drops below 12.1v. There are a number of models - all can be manually reset using a button on the unit, the Type II can be reset using a remote, and the Type III can be disconnected and reset using a remote, making it the most convenient, at the expense of another fob hanging around. The Type IV offers a manual switch which can be fitted inside the cabin for disconnection and reconnection instead of a plipper. This does away with the extra key fob (and a saving of £10) at the slight expense of having to manually open the door to reconnect the power if, as seems sensible, you have the switch inside the cabin. However a significant inconvenience is having to manually lock all the doors after turning the unit off, as none of them lock with a door open i.e. before I flip the cabin switch to disconnect the power. £60 for the Type III version with full remote is a bit pricey, even £45 for the basic version is expensive and still results in the same drain until it comes into play, so I think I'll opt for a mechanical under-bonnet switch as the doors will lock with the bonnet up, albeit at the expense of a polite warning beep from the horn. Subsequently realised the following points:
There is a completely separate cable from the battery to the starter which only carries current when the starter is operating, so I only need to interrupt the cable from the battery to the main fusebox, for which the smallest battery cut-off switch will be more than adequate. I looked at a DisCarNect which mounts on the battery post, but the two +ve cables on the ZS are crimped into a special battery connector and I don't want to have to cut that off and solder new lugs onto each cable. So I'm going for the same type of switch as I've used on the MGBs, which inserts into the a cable run. I could cut the existing cable and solder two new lugs but again I don't want to do that so a bit of lateral thinking is called for. The battery cable attaches to the fusebox with a conventional lug, so if I unbolt that and connect that to one side of my switch, then get another ready-made cable for between the other side of the switch and the fusebox I am sorted, and it can be restored to normal very easily. That leaves the clock and radio memory to be reset each time we use the car, but again that is solvable the same way as on the V8. Cut-off switches often come with bypass fuses, but all they do is prevent someone cranking the car when the switch is off, it doesn't stop the drain as all the electrics are still powered as normal. The answer is to remove the existing fuse (F8) and take a new in-line fuse (15A) from the live side of the cut-off switch into the fusebox, terminated with a male spade connector, and insert that into the load side of F8! Remember before doing any work on the electrics to disconnect the earth cable, not the 12v cable, and reconnect it last.
Just connected to two lengths of cable the switch would flap about quite a bit, so a mounting bracket is called for. The switch needs to be easily accessible, not block access to anything else as far as possible, and be clear of the bonnet. There is a nice triangular space between the fusebox and an air-con pipe that fits the bill, so next I need a couple of mounting points. There is a what is probably a suspension mounting stud with several threads clear of the nut, which should be suitable, and I can use one of the fusebox mounting points. I cut, shape and trim a card template to suit, then use that as a pattern for cutting a bracket out of a sound section off an old MGB wing, with additional flanges for strength. Cut, drill, bend and weld the bracket into shape, then paint. My previous two switches I have bought at the annual Stoneleigh spare show in February but I don't want to wait that long. Halfords have the identical item at about £12, but that is more than double what I paid, so I look around on the web. Several ads on eBay for silly money (like 99p!) which I just don't trust, plus some others at various prices all plus postage of course. Then I think of Min-Its only a couple of miles from me, a classic Mini specialist from which I've bought 20W/50 oil and some headlight parts recently. They have the same switch, and at less than £6 and no postage that gets my vote. The switch is actually intended to mount on the front of a panel, but that requires a large and irregular hole which would take most of the strength out of the panel, so I opt to mount the switch from the back which only needs a much smaller round hole. I don't want to leave the lugs and nuts on the bottom of the switch bare and risk shorting, so a couple of rubber covers at the princely sum of 44p each fits the bill. Min-Its didn't have these, nor a couple of local auto electricians, so they did have to come from the web and its postage charges, but very quickly (less than 24 hours) from Auto Electric Supplies Ltd. Halfords have a selection of ready-made battery cables in both red and black (£4 for 18"), and I have a spare inline blade fuseholder. I also have some split ribbed tubing to protect the switched cable and bypass wire, and some large diameter heat-shrink to seal that to the cables at the fusebox end as per the original, which gives an element of moisture sealing. I did find I had to open out the end of the original cable being moved from the fusebox to the switch to fit the switch studs, and also the switch end of the additional cable. I also had to trim a male spade slightly to fit in place of the original clock and radio memory fuse, as the spades on those are slightly thinner and narrower. There is still the drain of the clock and radio of course, but that is only about 9mA, and a significant chunk of that is the flashing LED in the radio (visible with the face-plate off and ignition off to act as a deterrent) which is off half the time reducing the current still further. Not long enough for me to see on my analogue meter, but it is less than 5mA. Original drain is about 27mA to 30mA (pulsing between them) so a useful saving.
The first time I reconnected the power using the switch the alarm went off, something it hadn't done when I had been removing the earth connection. I think the problem is that I had used the key fob to lock the doors for convenience while I still had the bonnet up, which sets the alarm, but when I reconnected power the doors were unlocked and one of them open as well as the bonnet. I recalled that the alarm 'remembers' its state even after a battery disconnection for security, so I'm not going to be able to lock the doors with the key fob before switching off the power, but will have to go back to locking the doors manually i.e. alarm not set before I switch off. I may be able to use the central locking from the key in the drivers door which doesn't set the alarm instead, before switching off and closing the bonnet, but will have to wait to test that for something other than a Sunday morning!
Bonnet Badge Added November 2012
Then we moved house and now the front of the car is only in sun for a short time each morning, so when I eventually get round to getting some new covers for Vee's tailgate props from Brown and Gammons I get a new badge as well. I'm not a fisherman, but scrounged some line off a pal of a pal. However that didn't seem to make any impression on the tape before breaking, maybe the cold weather is making the tape harder. I've got an old bicycle brake cable inner, so I peel a strand of that off, and being steel should be much stronger. Pull it back and fore over the shaft of a screwdriver to straighten out the spiral, and tie a loop in each end so I can use two screwdrivers as handles - and realise I have made myself a garotte!
It slides under the badge easy enough, and with relatively little pressure cuts through the bottom half of the tap and partly up the sides. There are two pegs on the back of the badge which stop it coming up all the way. But with that much done it's easy to get a fingernail under the bottom of the badge, and the top half comes away. The tape on the top half has peeled off the grille completely, but the bottom half where the garotte cut through is shredded with some stuck to the back of the badge and some to the grille, but again peels off easily with a fingernail, and I clean up the recess ready for the new badge. The garotte had put a couple of fine scratches on the edge of the recess, so silver or grey was showing through. With the badge offered up you would have to look very closely to see them against the silver badge surround, but the dealership mixed some paint for touching-up when I bought the car, and that was still liquid even though it was in a plastic mixing cup with a lid, and it was five years later! A fine brush soon covered the scratches.
I play a heat-gun onto the recess and the back of a badge to warm them up (holding the badge on my palm so I can be sure I'm not going to damage it or the grille), peel off the backing, and stick it in place. Don't go by the writing on the back of the badge, that is upside down compared to the logo on the front! Apply some pressure around the badge and job done, about half an hour.
Fronts: June 2013 Annoyingly failed the MOT on front brake balance - 34% and 19%. Absolutely no pull on the steering, which tends to confirm my theory that modern suspension alignment is such that the king-pin and tyre contact patch relationship prevents it, otherwise ABS would fling you one side or the other unless tyre grip was equal both sides, certainly not something to be depended upon. One thing I had noticed was a faint pulsing at the pedal, although only since I changed the pads, from the calipers as it slows with road speed i.e. not the ABS, which I've only ever activated on snow and ice and then only rarely. I had also been aware that the outer surface of the right-hand disc wasn't polished right across and had been like that since the pad change at least, but it was only when looking at the left-hand disc and finding that polished right across that I could see the reason for the imbalance. The calipers were fine when I changed the pads, i.e. piston movement and carrier movement, so whilst I shall have to spring for new discs and another set of new pads I'm hoping the caliper is OK. I'm very light on brakes, keeping my distance on motorways so I can usually control my speed just with the throttle, and on minor roads using anticipation to lose speed through deceleration except for the final stop. Sudden hard braking is rare. A pal says I need to be more of a hooligan and use them more, the Navigator would not agree! New discs and pads ordered, I'm expecting problems freeing the discs from the hubs. They have counter-sunk screws like MGB rear drums, and just as unnecessary in use as the wheels clamp the discs to the hubs. However I see from a photo when I changed the pads that the screws and the area of the discs where they are (one side at least) was clean and shiny then, so may come undone OK, but the centre hole may be a different matter as that is a snug fit to centralise the disc on the hub and is showing rust. Before ordering the parts I need to check the calipers are free both in terms of the piston and the sliding carrier on each, which they are and is a relief. And while I'm doing that I might as well see how much of a problem I'm going to have getting the discs off. Right side screws come off just with a screwdriver, the disc needs a couple of taps with a wooden mallet so each enough. The left side screws were tighter so before I damaged the slots I used my impact driver on them and they came undone ... and that disc just fell off. Ordering the parts it was a toss-up between MG Rover stuff from Rimmer at about £170 plus P&P, or Mintex from eBay at £115 inc P&P and I opt for the latter - noting that discs and pads for the MGB would be less than that. With these discs having to be replaced in 9 years and 40k miles, whereas the V8 discs are originals at nearly 40 years and over 200k miles, I don't think the extra cost is warranted. Maybe change my mind if these discs have to be replaced in 4 years!
Parts ordered Friday pm and arrive Monday am, good service from Motor Spares Dewsbury. Discs (Mintex) have some sharp edges, so watch your fingers, I wiped the surfaces off with brake/carb cleaner and a clean cloth to remove surface oil from manufacturing. The pads (also Mintex) have huge chamfers on the leading and trailing edges maybe removing as much as a third of the initial contact patch, which will increase as the pads wear down, probably not reaching the full contact surface until they are one third worn. One thing to note is that these are bare pads, if yours have been on a long time then I'd recommend getting MG Rover pads as these come with anti-squeal shims for both the pads and the pistons, anti-chatter springs for the carriers, and even new caliper bolts. Changing mine last year the caliper bolt heads had rusted quite a bit, one needing an under-sized socket hammered on before it could be undone.
Removal was easy as everything came undone easily this time, it took more time fiddling the pads into the anti-chatter springs on the right-hand caliper than anything else. Copper grease on centre hole of the discs, and the locating screws, as well as the caliper bolts. If I thought the outside of the right-hand disc was bad, the inside surfaces of both were dire. As well as being different amounts of clean metal on each, giving the unbalanced braking, I can also see that the amount of clean metal varies around one of the discs, which will give the pulsed braking I have increasingly been able to feel. Back together a static test showed much less sinking of the pedal than with just the pad change. A short drive and several moderate braking checks from about 50mph has good feel and retardation, and back home both discs show even initial marking from the pads so hopefully not much bedding-in required. Next day the MOT retest is successful, even though I can see slight imbalance between the sides on the braking machine when both are checked together, possibly just needs fully bedding-in.
Rears: September 2013 Last MOT there was an advisory that the right rear was grabbing slightly. Nothing this year but a couple of weeks ago I noticed some brown staining on that wheel, then a couple of days after that it was squeaking when going backwards. Thought it might be the wear indicator so had a squint at the outer pad and it seems to be worn down to the backing, whereas the left outer has bags of meat left on it - I wonder if the right caliper is sticking ... Order a pair of discs and pads from the same place I got the fronts and they arrive in a couple of days.
Get the right rear wheel off, and the first thing I do is check that the disc screws will undo. A bit tighter than the fronts were, but still came undone with my impact screwdriver and a mallet. Next was to push the piston back in, as you can never get pads off the edge of old discs as they are thicker there as well as being rusty. Piston doesn't want to move, maybe the caliper is seized. Oh well, see if I can get them off anyway.
Next was to remove the carrier complete with caliper and pads from the hub, and compared to the fronts that is a bit of a fiddle. My socket only just goes on the lower bolt - really it needs a slim-line socket as it is very close to the suspension arm, and I have to try various extensions before I can undo both. Try and remove the assembly from the disc, but it jams before it has got half-way, that piston simply isn't moving. If it is the caliper then the other one might be as bad, so refit that side and have the same battle with the other side, with the same result. Hmmm, both calipers seized? I refit it and get the navigator to pull the handbrake on and off, and press and release the foot brake while I turn each wheel, and both wheels are braked and released as they should be, so what's going on?
Off to the internet to have a browse, and I discover that because the handbrake acts on the pads via the caliper piston, there is a ratchet mechanism behind the piston that acts as a self adjuster for the handbrake as the pads wear, and you have to wind the pistons back in with a special tool, you can't just press them back in! So that's what going on. Haynes doesn't say anything about that in disc replacement, but it does in pad replacement. It also says to remove the caliper, carrier and pads complete when changing the disc, but as I've discovered that is unlikely to be possible with old discs. It looks like I'll have to disconnect the caliper from the carrier and lift that out of the way, and then remove the carrier with pads, before I can get the disc off. But as one has to press the piston in while turning it, I may have to remove the caliper, remove the pads, remove the carrier, remove the disc, refit the carrier, and refit the caliper so as to hold it firmly while I press and turn the piston! Then remove the caliper again, remove the carrier, fit the new disc, refit the carrier, fit the new pads, and refit the caliper - quite a palaver. One of the internet sources I browsed has a link to a source for the rewinder. They are just a couple of miles from me, but as they do free postage and I have run out of time anyway I opt to order online and it arrives in a couple of days.
This time I remove the caliper from the carrier. Top bolt is fine but the bottom bolt is shrouded by the hydraulic pipe, that would have to be disconnected with the inevitable need for bleeding in order to get a socket on it. I do have a 12mm ring spanner, but it is a ratchet ring and I don't like using those for the initial undoing of a nut, but I don't have any solid metric rings. Nevertheless I give it a go, and a few taps with a mallet shift that one on both sides. Caliper comes off quite easily, and can be suspended from the rear box bracket on the drivers side, and a hole in the inner wing (for the fuel pipe cover that was fitted to early cars) for the passenger side. I remove the pads from the carrier while that is still attached to the suspension arm as they are quite tight and need to be drifted out. If had removed that first I would have had to clamp it in a vice. Drivers outer pad completely worn out, inner pad nearly so. Passenger pads well down. Next the carrier comes off - for some reason it was much easier to get a socket and short extension on the two bolts this time, and finally the disc.
I had wondered if I would need to reattach the carrier to the suspension arm, and the caliper to the carrier, to hold it firmly enough to be able to screw the piston back into the caliper with the rewinder, but it turned quite easily. The rubber dust-seal did start to snag a bit as the piston was nearly fully in as the edge of the piston was quite rusty, so I wound it out again and used a small file around the edge to clean it up which allowed the piston to bottom without twisting the seal.
Clean up the new disc with brake cleaner and fit that. Refit the carrier to the suspension arm, with a smear of copper-grease on the faces of the retainer spring that butt up against the edge of the pads. Fit the pads, the outer goes in fine, but the inner goes so far then stops. Peering round the back I realise it is the wear indicator spring, the free end has to be lifted up with a screwdriver so it fits over the edge of the carrier. The biggest potential problem is that these Mintex pads are bare pads i.e. no springs, shims, and sliding pin bolts that the pukka MG Rover front pads came with. I discovered that when I changed the front discs and pads, but there the 'missing' items had only been fitted a couple of years previously so bare pads were fine. I had forgotten that for the rears, I should have got just the discs and got pukka pads elsewhere even at the higher price. Fortunately the springs are fine, the shims for the backs for the pads are pretty corroded but are just about OK to reuse. Copper grease on both sides of the shims, and the caliper slides over them - I had wondered if there would be enough clearance with the corrosion on the shims. Then it's just a matter of refitting the sliding pin bolts, tightening them and the carrier bolts, and refitting the wheel. The handbrake comes up a helluva long way to begin with after doing the second side (didn't seem much different after the first), but after a couple of pumps on the foot-pedal and raising and dropping the handbrake a couple of times it settled back down to a more normal position. Quick test-drive round the block, footbrake is fine, but the handbrake is (still) pretty poor, but then again the pads need to bed-in. About 2 hours for both sides, including setting up i.e. jacking under the boot floor before putting axle stands under the sill supports just in front of the wheels, then packing everything away. All-in-all easier than I was expecting.
Brake Pads Added June 2011
Updated June 2012: MOT looming so decided to change the pads anyway. Still plenty of meat, I reckon at least as much again from the wear indicator touching the disc, but I might as well. All pretty straight-forward, I just had to clean a bit of corrosion off the carriers before I could get the new springs in, but that's all. One initial concern on pushing the pedal afterwards to push the pistons back out before driving off (I don't want a repeat of the V8 where I forgot once and had no brakes when rolling off my sloping drive!), engine running, was that the pedal went a long way down even after having reset the pistons, and under heavy pressure seemed to be sinking. However it stopped before reaching the floor, and driving even when pressing the pedal quite heavily to bed the pads in it didn't seem to go down anywhere near as far, and in normal driving it felt the same as before. The thing is I've never sat with the engine running and pressed the pedal very hard before, so I don't know what it was like before, could just be hose expansion. However the following year it failed on front brake balance, the discs had always been ropey, so had to change them ... and consequently the pads again.
Cambelt Change Added September 2009
I then spent some time peering around the engine working out just where I had to get to, immediately realising the very restricted space at the front of the engine where the primary belt is. I've got quite a comprehensive tool kit with 1/2", 3/8" and 1/4" drive metric sockets, ratchet spanners, torque wrench, 30" breaker bar. You also need T30 and T55 Torx drivers, and an 8mm Allen key. There are a number of specialist tools required, most of which are to ensure the correct alignment of the four camshafts and crankshaft, which is absolutely vital. These are available in a kit, but the kit contains the tools for several different versions of the engine and is pretty expensive unless you intend to this job on a regular basis! However Haynes details a method without using these special tools, but which does require fabricating some oneself. The most important two of these are the flywheel locking pin to hold the crankshaft in a known position, and a forked tool to hold the various sprockets steady while loosening and tightening their fixing bolts. Again it is very important not to transmit these forces along the camshafts or through the belts. It was only after making these tools that I purchased the various parts required for the change:
I did remove the under tray but didn't remove the right-hand wheel arch liner, it didn't seem necessary on my 2004 model.
I have a battery cut-off switch so didn't disconnect the battery. I found I didn't have to remove it, or the battery tray or move the ECU as stated (these steps are probably necessary for removing the engine, and is one of the drawbacks of the format of these manuals). Neither did I remove the spark plugs, that looked a lot of work and very awkward at the back of the engine, and it is easy enough to turn the engine over against the compression anyway.
I disconnected all the plumbing and wiring around the engine as recommended in the early stages, but didn't remove the inlet manifold itself until after I had changed the primary belt. This was because getting at the primary belt was obviously going to be the most difficult part, and I didn't want to do any more work on the 'easy' side than I had to in case I had to abandon the job. I had to disconnect the fuel feed pipe to get the manifold off, something which isn't mentioned in the manual. Most are pretty easy - depressing locking collars to remove the pipes, although the small bore vacuum pipe is a tight-fitting push-on rubber connector which needs to be levered off from below. Most of the electrical connectors are also straightforward with various locking tabs and springs, although one on the purge valve you have to depress two white bits into a recess which is a bit of a fiddle. 'Unclip the rear ignition coil wiring harness from the manifold' is a typical Haynes understatement. All I could see was what looked like two cable ties, so just cut them through. It was only after the manifold was off that I could see they were specials with pegs that pushed through the manifold bracket and expanded behind it, impossible to see that in-situ let alone squeeze the pegs to 'unclip' them! It wasn't a problem though, I pulled the cut-off end out of the slot in the fastener, cut the attached end off, then could feed a plain cable tie though the slot and fasten it as normal. But that is a long way away yet.
Inserting the flywheel locking pin is an early step, and took me ages to sort out as the instructions are wrong. There are two holes, and Haynes says the outer is for the flywheel and the inner for the locking plate if an automatic gearbox is fitted. I just couldn't get my locking pin inserted, although I could feel the hole and it limited the movement of the crank if I inserted a small screwdriver or undersized bolt. I thought maybe my pin was too big, so progressively reduced the diameter, but to no avail. I was tempted to use the smaller bolt, but was concerned about it falling out half-way through. Eventually I managed to peer inside the holes with a torch and mirror to find that it was the inner hole I should be using! That must have taken almost an hour of faffing about, and I'm not even sure why it is mentioned so early as you have to take it out again to undo the crank pulley nut, and it is only really required after that.
My 2004 model differs slightly around the right-hand engine mount to Haynes, but it is easy to see what has to be done. From this point the sump is supported on a block of wood on a jack, and one is continually moving this up and down to get at various bolts. I initially left the power steering reservoir and upper steady bar rear bolt in place, lifting the steady bar itself up and back, but did have to remove them altogether later on. Not mentioned in Haynes are two small bolts connecting an air-con and an oil (?) pipe to the bottom of the engine lower mounting bracket, and these were really fiddly to get out let alone put back! Some of the bolts in this area only have an inch or so clearance to the side of the engine bay, so you need sockets to be as low a profile as possible, maybe even grinding some down so the head only just fits in, or you won't get them in the space available.
You use the T30 torx driver to slacken the three screws on the power steering pump pulley while the belt is still on and under tension to hold the pulley still, removing them once the tension has been released and you have lifted the belt off. The T55 Torx driver is used on the idler pulley, which doesn't need the idler pulley to be held still. Removing the primary belt rear upper cover is a fiddle. It's easy to drop small bolts and sockets, which I did two or three times. The first time the socket appeared right out by the wheel hub on top of the lower wishbone after a short search, the second time I couldn't see it anywhere and it only fell out while I was moving the engine about later on. One of the cover bolts remained hidden until I had the car running again, when it fell out further down the drive.
This is where you MUST remove the flywheel locking pin if it was inserted earlier. Failure to do so will probably shear it off inside the flywheel or do other damage. Needless to say the crank pulley bolt is really tight, 118 ft lb! No chance of undoing it from below without a pit or hoist, but at least I can get a breaker bar in from above. Fifth gear selected, with the Navigator standing on the brakes, but the force required is such that the movement of the crank in the engine, engine in the bay, and the bending of the bar takes up all the swing space with out cracking it. However by removing the power steering reservoir and upper steady bar and rear bolt I gain an extra couple of inches, and end up with just 1/2" to spare before the bolt moves. When the bolt is slackened, but the pulley still held on its keyway, re-align the notch (it's tiny, mark it with white paint) in the pulley with the SAFE mark on the front cover, and re-insert the flywheel locking pin. It is essential to keep this pin in place from now on. At the other end of the engine with the air cleaner and intake hose out of the way you should be able to remove the front secondary belt cover. Check the notch in the lower (exhaust) sprocket is facing the upper (inlet sprocket). If not the flywheel locking pin should be removed and the crank pulley turned 360 degrees so the SAFE mark is aligned again, and reinsert the locking pin. The notch in the secondary belt exhaust sprocket should now be in line with and adjacent to the groove on the inlet socket. The notch is on the back of the exhaust sprocket and the groove on the front face of the inlet sprocket, so check the alignment with a straightedge. Put paint marks on the backplate and sprockets now, even though you aren't going to be touching the secondary belts for a while yet.
There is no locking collar on my dipstick tube, its metal end just pushes into a hole in the casing. Slightly concerning as the oil level is normally above this (which is why you have to drain the oil before this point), although it doesn't seem to be leaking ... yet! There is a bracket and small bolt further up the tube, behind the idler pulley, not mentioned in Haynes. You need to remove the dipstick tube to allow more room for the oil cooler hoses to move with the oil cooler, but even then there isn't enough movement on the oil cooler to get a straight run at any of the three air-con pump bolts. These are very tight at 63 ft lb even they only have 10mm heads. I only discovered a damaged 10mm 3/8" drive socket at this point, and broke a 1/4" drive socket and adapter undoing them. I could only undo the upper bolt using the breaker bar pushed in under the wheel arch and between various pipes and hoses, fortunately I had just enough swing using a 16-point socket. The lower bolt just above the oil cooler needs a very low profile socket and driver. These three bolts were one of the hardest parts of the job.
More low-profile sockets are needed to undo the two lower rear bolts from the engine front plate, and more manouvering of the engine to get the top rear boss-bolt out. Getting the cover itself off is another very tricky operation, as it has to be lifted, tilted and twisted by varying amounts at different times. The very restricted space compounded by an air-con hose in the worst possible place conspires to make this very awkward. Even worse getting it back on as you have to prevent the edges of the cover damaging the edge of the new belt. Recover the rubber tensioner cover, which could be lying in place or dropped somewhere by now.
At this stage I removed the inlet manifold (plugging the intake holes to prevent anything dropping down them) and secondary belt covers, and marked the rear exhaust and inlet sprockets and covers as per the front ones.
Next the primary belt tensioner and a major error in Haynes. It says to loosen the two tensioner body bolts, then release belt tension by turning the tension clockwise with an (8mm) Allen key in the tensioner wheel. However turning the Allen key clockwise adds more tension to the belt. But this is the correct thing to do, if you attempt to release tension by turning the Allen key anti-clockwise, you will undo the Allen bolt which will destroy the setting of the tensioner wheel. By adding tension to the belt you lift the wheel off the tensioner, which allows you to remove the bolts without them being under tension and pinging off somewhere. As you then release the tensioner wheel, the belt will slacken and the rear cam sprocket rotate under valve spring tension. The front sprocket should remain where it was as it is held by the belt going round the locked camshaft. Be careful not to disturb the belt in the sprockets until you have painted alignment marks on the two covers and sprockets. It might seem odd only painting marks after releasing tension, but it is easier to get the new belt on and the sprockets in their correct positions this way. If you paint the marks before releasing the tension then you will have to keep applying full tension and releasing it again if you need to move either sprocket.
As you take the belt off the front sprocket will move, and the rear sprocket will move more. This is normal, but don't turn the sprockets any more than that. When fitting the new belt you will need the soft wedge under the crank sprocket, as that is your reference point. Lay the belt over the idler wheel, turn the front sprocket clockwise (you can use a spanner for this as it is effectively tightening the bolt, not loosening it, which you must not do) and lay the belt over this sprocket so that its marks are aligned again when the belt between it and the crank is under tension from the sprocket. Lay the belt under the water pump wheel and loosely over the rear sprocket, turning the sprocket anti-clockwise with the forked tool (not the bolt), such that its marks are also aligned when the belt is finally laid over the tensioner wheel. I found the new belt was more prone to jumping out of the sprockets, so had to have two or three goes to get the alignment correct. When you think it is, double-check the alignment marks on the secondary belts as well. When all are correct you can refit the tensioner.
I had imagined this was a simple spring and would be relatively easy to compress but no. I did have to put it in a large vice, and it took a lot of pressure to start closing up, less after that, whereas one would expect a spring to get harder the more you compressed it. A suitable-sized pop-rivet served as a locking pin. With the tensioner bolted into place I also imagined I would have difficulty pulling this pin out as it is ostensibly holding back quite a bit of tension. But with the tensioner wheel resting on it came out quite easily. All things considered I reckon it must consist of some very slow-acting compressible material rather than a simple spring. With the belt now under tension you remove the flywheel locking pin and soft wedge under the crank sprocket and turn the crank through two complete revolutions then reinsert the pin, which should put the secondary sprockets back in their aligned positions, double-check this to be sure before proceeding with refitting the front plate and starting on the secondary belts. With the front plate back on refit the tensioner rubber cover. It took a bit of working out just which way round it went!
For the secondary belts to undo the inlet sprocket bolts you must use the forked tool, don't undo them against resistance from the camshafts or belts. It's safest to align the tool and a breaker bar on the socket so they are a few degrees apart, you can get your hands round both, and squeezing them together will loosen the bolt. This ensures that there is no torque on the camshaft if the forked tool should slip. With the bolt removed the sprocket has to be levered of the keyway, when it comes loose it will simply fall off so be ready for it. Again the exhaust camshaft and sprocket will move, but the inlet won't as it is held by the primary belt. On my engine the exhaust sprocket moved three teeth, so when I fitted the new belt to the exhaust sprocket and inlet sprocket to the belt I put the inlet sprocket three teeth out in the same direction. Haynes recommends a tapered pin now to get the new bolt inserted, but it simply isn't necessary, on mine both screwed straight in, although the sprocket and cam keyways weren't aligned of course. Haynes now says to use the 'flat bar tool' to turn the inlet sprocket into alignment. However I found the slots in the sprocket were so shallow that it needed two hands to hold the bar square while turning the sprocket against valve spring pressure, which left me no hands to tighten the bolt, using one hand on each it kept slipping out. Eventually I screwed the bolt in just short of taking up all the slack, and simply used the forked tool to turn the inlet sprocket, which via the belt turned the exhaust sprocket, and when the exhaust sprocket notch was aligned with its paintmark I checked the inlet sprocket paint marks were also aligned, then simply screwed the bolt in a bit more which pulled the inlet sprocket onto its keyway. Could have been a fluke, but both belts were as easy as that, so I'll leave it for you to judge.
Tightening the bolt must be done using the forked tool again, again a few degrees apart from the torque wrench squeezing the two together. From the correct torque it much be tightened another 90 degrees. I jibbed at spending £15 on a degree wheel so downloaded a jpeg from the web, printed it out and stuck it on a piece of card, varnished it, and cut a 1/2" drive hole in the middle - just the ticket.
After that it is a matter of refitting the removed components. I simply worked backwards though my list, although the dip-stick tube needs to be fitted between replacing the primary belt front upper cover and the aux belt idler wheel. When fitting the aux belt to the grooved pulleys it is important to check it is sitting in the grooves as recommended in Haynes. I thought I had it on the alternator pulley OK, but when I checked the clearances between the sides of the belt and the edges of the pulley I noticed a difference one side to the other, whereas all the other pulleys had an equal clearance both sides. Releasing the tensioner and pushing the belt slightly I felt it drop into the grooves, and the clearances were now equal. Note that the clearances vary from pulley to pulley, but each pulley should have the same clearance both sides. More struggling with getting all the parts back on the front of the engine. I couldn't get the torque wrench on all of them, so had to settle for testing the ones I could do then repeating the same amount of effort on the others.
The three seals in inlet manifold VIS unit came out easily, there is a handy bit sticking out from a slot you can lift up with a fingernail. Getting the new ones back in is equally easy, tilt the seal so the outer edge by each of the ribs in turn is in the slot, then press with the back of a fingernail on the inner edge and it will go in the slot. Likewise the O-rings on the alloy were levered off with a small screwdriver, and new ones pressed over the lips. When offering up the VIS unit to the engine you need to lay out all the connectors and pipework that remained on the engine in their correct positions ready for reconnection. There are only two tubes that come up between the throttle body and the VIS unit - the thin flexible vacuum pipe and the much stiffer servo vacuum pipe, and these should be fed through as you lower the VIS unit down. The thinner pipe is easy to do afterwards, the other one less so. Possible, but it could crack the pipe on a cold day. The fuel pipe also needs to be lifted up out of the way then laid back over the VIS unit and throttle body. Due to different connectors and sizes of pipe etc. it is easy to get everything back in its right place, don't forget the breather on the rear cylinder head which is partly concealed under the VIS motors. Change the oil filter if you haven't already done so, refill with oil, select neutral, reconnect the battery, and with heart in mouth switch on, and if everything looks and sounds normal go for a start. After a few moments checking for oil leaks and anything else untoward I switched off and refitted the road wheel, but left the under-tray until after a road test.
So, the first three objectives met - get everything back with no bits left over; get the engine running; go for a test drive. The fourth objective is not to have anything fail over the next several thousand miles! Would I do another? Well, I was on the verge of giving up a couple of times as things around the front of the engine and particularly the air-con compressor were so difficult to access, so I would have to think very carefully. Would I do this one again? The old belts were perfect so probably didn't need changing there and then, but then again how long after any visible deterioration appears will they last before breaking? The exhortations about using the time interval for cars doing short start-stop journeys rather than mileage probably relates to those cars regularly doing those sorts of journeys five or more days a week, whereas this car is rarely used more than once per week, and can go several weeks without being used at all in fine weather. Whilst there will be some hardening of the belts occurring over time when it isn't being used, I could probably afford to go several years longer next time, maybe splitting the difference between the mileage limit and the time limit. At 3k per year it will take me 20 years to do the Haynes limit of 60k, so half way between that and the 3 year limit means 10 years in round numbers. By that time I'll be over 70, so I probably won't be capable of doing it anyway!
Cooling Fans Added May 2009
With it out of the way it was immediately noticeable how easy it would be for small persons to stick their fingers in the fan while daddy (or grandad) had the bonnet up. Two holes in the grille but couldn't immediately see where it would attach. Roger Parker at the MGOC opined it was either a security grille (in which case it almost certainly would have been metal) or a safety grille, and forwarded a page from the Parts Catalogue showing it more or less where I found it, with two blind fixings to secure it to the armature.
Fiddled it back in, but need to see if I can get some fastenings as it is just rattling around, although it does protect the fans a bit better. It was apparently a face-lift change, maybe after reports of injuries. If the guards on the fans themselves had been a bit deeper it wouldn't have been necessary.
Apparently the crankcase breather system can deposit oil into the throttle body, which gets into the intake unit, and gums up the butterfly pivots which is what burns out the motors. The visible symptom before the motors fail is said to be oil coming from the air filter housing drain and dropping on the ground. Once the motors fail you no longer get the benefits of the variable intake system which hits both performance and economy. Another symptom of a failing or failed unit is said to rattling from the butterfly valves. I've been able to feel the effects of first two changes in intake length so at least mine were working, and no oil drips. I removed the air filter and there was just a line of sticky oil on the lowest part of the plastic frame for the filter material, and signs of oil having run down from the throttle body into the filter housing. In the grand scheme of things this is classed as very 'minor' oil contamination.
So I take off the concertina hose between the throttle body and filter body, to find more liquid oil lying in the folds of the hose - not so good.
Then look up into the throttle body to find liquid oil all around the bottom of the butterfly, that forms a column as the butterfly starts to open - even worse!
So I'm pretty sure I should fit a catch tank, but then wonder to myself that if I stop fresh oil going into the intake unit, will that cause the oil that is there to go sticky and so cause the problem? It's being so cheerful as keeps me going, as they say. So now for this catch tank. One person recommends one from a well-known MG parts supplier, which costs £73! Large alloy box with an external glass tube so you can monitor oil level, but the problem I and others see is that the inlet and outlet pipes are so close together that while droplets of oil may fall down from the inlet any oil mist will go straight through unless there is an oil-trap filter mesh between the two! Do a search on Google and find an eBay supplier that shows a photo that looks externally identical to the £73 item, but this is only £14! I write and ask about any mesh between inlet and outlet, and there isn't any so I'm not happy about even the lower price. On one of the many MG-Rover.org posts on the subject someone mentioned they had used a petrol filter, which seemed like a neat and cheap alternative to me, and being translucent you can see any oil building up in it, and they are throw-away service items of course.
There is also quite a lot of discussion as to just where in the breather system it should be connected to. There are two halves to the system, each half having a pipe that comes off different places on the throttle body, to a tee, and then to each cam cover on opposite sides of the engine. A larger diameter hose comes off the forward part of the throttle body, between the butterfly and the air filter, this hose is at atmospheric pressure and supplies filtered air into the crankcase. The smaller diameter hose comes off the throttle body on the engine side of the butterfly, so is at a significantly high vacuum whenever the engine is running at anything less than full throttle. This is the suction side that draws fumes and vapours from the crankcase to be burnt in the engine. It is this pipe that picks up oil mist and deposits it into the throttle body, to be sucked backwards into the intake unit, and to run forwards past the butterfly into the air filter. Some say the catch tank should be fitted into the large pipe (wrong!) and some into the small (correct!). It can be seen that because the airflow is from the air filter, through the large pipe, through the crankcase, through the small pipe and into the throttle body it must be in the small pipe to do anything at all. Some say you need two catch tanks, which you could fit but the one in the large pipe would probably do nothing useful but it wouldn't cause any harm. Some say you can run both pipes via a single catch tank, but this is the worst option of all and definitely should not be done. By connecting both pipes to one tank the first thing that will happen is that the small pipe going to the throttle body will take the vast majority of its air direct from the large pipe coming from the air filter, and virtually none will go through the crankcase. This may well stop any oil getting into the engine, but it won't be removing fumes and condensation from the engine either i.e. it kills the breather system. But by far the biggest effect will be to introduce a massive vacuum leak into the inlet manifold which will have a huge effect on running. In the breather system there is a restriction that controls just how much air can be pulled through the engine and fed into the inlet manifold, and it is a very small amount. On the MGB the restriction is on the fresh air inlet side, which is either inside the oil filler cap on cars without a charcoal canister, or in the port on the back of the rocker cover on cars with a canister. This keeps a small negative pressure inside the crankcase at all times. On the ZS I don't know whether the restriction is on the inlet or the outlet, but it is there. Subsequently removing the oil filler cap didn't change the engine note, and even laying a sheet of paper over the hole revealed no vacuum. But disconnecting the small pipe between the engine and the upper throttle body caused the engine to race, so the restriction must be in the small pipe before the engine. Probably deliberately, otherwise removing the oil filler cap would cause the engine to race, rather than there just being a slight change in engine note as on the MGB. The difference is because the ZS uses full manifold vacuum as a source, rather than the very low vacuum from the carbs and earlier PCV valve of the MGB.
I have an MGB fuel filter with inlet and outlet ports pointing straight up and down. The problem with this is that it needs to be upright with the inlet at the bottom and the outlet at the top, so oil doesn't soak through the filter and run to the outlet anyway, which it might if the filter lies on its side. Ideally it should be mounted above where the pipe connects to the engine so any oil that gathers will run back down, but because the pipes are at the top of the engine there isn't enough clearance to the bonnet. Someone also mentioned a right-angle filter, which seems a good idea as that would lead less vertical space and would help to keep the filter vertical. A trip to Halfords revealed a right-angle filter at just under £3.50 (HFF202, cheaper than the in-line port type the MGB uses!) and a metre length of 8mm or 5/16" hose with clips for £4.30 (HFH402). This size of hose is a good compromise to fit the breather hose and the ports on the filter.
Now the point of no return - to cut the existing breather pipe. I did this about mid-way between where it joins to the throttle body and the tee, at a right-angle bend. I cut on the throttle body side of the bend then swivelled that half of the pipe round to face more or less the battery, which was the area I had decided to position the filter. I was going to cut the angle off the other half of the breather pipe, but instead used a paint gun to soften it and a drill shank inside the pipe to straighten it. A 3" length of pipe needed a firm push to get it onto the breather pipe so won't need a clip, but is a looser fit to top horizontal port on the filter so clips will be needed on both filter ports. A longer length of hose will be needed to connect the port on the bottom of the filter to the engine half of the breather pipe. This needs to be long enough to go vertically downwards from the filter then round, up and across, and fed round and past various pipes and cables in a series of smooth curves, to join to the breather pipe to allow the filter to be secured in an upright position, I probably used not much more than a foot of the metre length I had bought. Again a tight push onto the breather pipe and a clip onto the filter. Finally a cable tie secures it to the main cable from the battery to the fusebox. Started the engine to check all was well, and was a bit startled to hear a slight rattling coming from the intake unit! Now I can't say I have ever noticed this before, but I can't say either the last time I ran the engine with the bonnet up, and I may only have noticed it because of recently reading up on the problem. Nothing I can do about it now, I've got a couple of hundred mile journey coming up tomorrow, so I'll see what effect the filter has on trapping any oil. I had already decided I'm going to have to remove the throttle body and intake unit to flush them out as best I can, but that will have to wait for warmer frost-fee weather so I can use the V8 as a daily driver while I'm doing it. There are also going to be things to check on the VIS motors and limit switches, which can also gum up and cause other problems.
After reading lots of experiences and opinions and thinking on them I have come up with a number of what I think are salient points:
Update April 2009:
Update May 2010: After building up a little oil in the bottom it didn't seem to get any more. Looking at the filter it is marked 'inlet' and 'outlet', and that is the direction of breather flow. However despite what Baldwins told me above it seems more logical that the outlet will go down the bottom, to ensure it gets fuel even if there is air trapped at the top, the inlet pouring in at the open top. That's certainly how the V8 filter works, which can be almost completely full of air and yet the engine still runs fine. Pouring a little petrol into the filter and blowing into each port in turn certainly seemed to confirm that, which means it has been sucking oil out once there was enough to cover the bottom! I've enough slack on the hoses to cross them over, so I'll see what happens from now on.
Headlights April 2014
Quite by chance almost to the day the MGOC mag arrived containing an article by Roger Parker on just this problem. He recounted how a local valeter had solved the problem for him with his magic potions, so I've contacted the same chap to see what he can do for me. He wanted £60, so I contacted a couple of other valeters in my area to see what they said. No more quotes, but one was kind enough to send me a link to an Amazon page of DIY products. 3M had the most comments, almost all positive, and that was £20 but didn't include a UV protector to put on after the cleaning process. Turtle was much cheaper but mainly negative comments. Another product priced between those two had mainly positive comments, although only six in total. But by perusing the products it seems that most of them contain various grades of wet and dry abrasive paper from 1000 to 3000 grit, then a polishing compound, and some include a UV protector spray. I've got some 1200 grit, and some Solvol Autosol, so decide to have a go on an unobtrusive corner. As expected the wet and dry - used wet - immediately leaves a matt grey surface, but by alternately rubbing and drying (You can't see the coating until the surface is completely dry, so a warm dry day is best) I can see that the coating is being removed. Then polishing that area vigorously with a Mk1 digit in a cloth with a bit of Solvol Autosol on it, brings it back to clear again - so worth a go.
Scour the internet for suitable abrasive paper, and purchase 2 sheets of 2000 grit and 2 of 3000 grit from The Polishing Shop. This company allows you to buy exactly what you want in terms of numbers of sheets, and have 18 grades available, and were also good value. Most other vendors only have packs available. In the end I only used one quarter of a sheet of each grade for both headlamps, so could have saved even more money!
I had decided to take the headlights out as I reckoned that would be easier than masking round the wing and bumper - but that's easier said than done. Four plastic fittings on top of the bumper, four bolts underneath, and two more at the sides up into the wings. There is also a plastic clip just a couple of inches forward of these last two, very brittle, and both mine snapped when taking the bumper off a few years ago two fit a decent pair of horns. It doesn't seem to suffer without them, Rimmers and Lakeland Minis have them (DYC101340) although the latter want £5 to post two clips costing £2! Ease the bumper forward to unplug the fog lights, try to part the grey connector for the temperature sensor but no go. However while struggling with that the clip securing the pair of connectors to the bumper came free, and it was a moments work to unclip the sensor itself.
Next you have to remove the plastic structure that goes across the front of the car, which is the real 'bumper' as opposed to the external panel. Four bolts easily accessed - but two of mine were well seized. Fortunately I could get WD40 on the backs and by working them back and fore finally got them out and the structure off.
The headlights have two bolts on top, one at the indicator end into the wing, and another one underneath by some kind of electrical device with heat-dissipating fins. However with the first three removed on the left-hand light, it was free, the bracket for the lower one had fractured. Two wiring plugs to remove - the black one was easy, and again the grey one was difficult, but finally came free. Took the headlight to the bench for wet sanding. The problem is that the shape underneath and at the back doesn't make it easy to support firmly and safely, paying special care to the bulb holders. I supported it on a block of wood to protect those, and as I was hand sanding could hold the unit steady with one hand. Starting with 1200 grit I concentrated on the areas that had remaining factory coating, periodically wiping off and drying to check progress. It's only when completely dry that you can see if the coating has been completely removed or not, tilting it at angle looking for edges, so a dry and sunny day is best. I was surprised how little time it took, probably only about 10 minutes When the coating is fully removed move up to 2000 grit, which visibly reduces the fine scratches left by the 1200, and then the 3000 grit. It's ironic that when wet the lens looks completely clear after this stage, going 'smoky' again when it dries.
For polishing I decided to put the headlamp back loosely, as I would need both hands for the drill and polishing mop. But while out I masked the remaining few inches of body-work that was round the headlight - the wing - using duct tape for strength but ordinary masking tape underneath that in case the duct tape adhesive was a beggar to remove. Smeared Solvol Autosol over an area of the lens with a finger-tip, then used the electronically variable drill on its slowest speed, and light pressure on the mop. It very quickly brought back full clarity to the lens - very pleasing. Bear in mind that too much speed and/or pressure could create excessive heat and score the plastic. Wiping off the residue with a clean duster created quite a bit of static, but an application of Plexus removed that and left it crystal-clear.
The second headlight I decided to wet-sand in-situ, partly because of the risk of damage as I mentioned earlier, but mainly because I simply could not get the grey connector out. Undid all the bolts as before so I could move it out of the way to mask the wing, then loosely refitted it. Much easier working with it firmly held. This one took probably two or three times more effort and time to shift all the original coating, but eventually did, then polished up as easy as before.
Refitted the headlights and reconnected the wiring, then checked all the bulbs worked before refitting the armature or bumper! All good, so refitted the armature, with copper grease on the bolts. Discovered there is a dinky bracket remaining on the body, that you can hang the armature on while fitting the bolts, so you don't need one hand to hold it while you struggle with the other to line up the holes and get a bolt in. Hung the bumper in place with its top four screws, then refitted the fog light wiring and the temperature sensor. Again, checked the fog lights worked at this point. A bit of a struggle getting the bumper to go fully back, until I realised there are two pegs on it that fit into slots on the armature, again to hang the bumper while you are fitting the screws! Used copper grease on the four bolts underneath and the two at the sides as they were also variously stiff and rusty on removal.
Ordered some UV spray - there seem to be two types, one looks like a plastic coating where I would have to be very careful not to get overspray anywhere else, so passed on that one. Settled for Glass Sealant, UV Inhibitor and Coating which at £12 delivered is by far the most expensive part of the job. No instructions, but it's a cream so I squeezed it out on to a clean cloth and rubbed in, then polished off with a clean soft cloth. Lens maybe very slightly brighter after that, many droplets formed in rain later that day, so it's done something. However I used hardly any even though I did two applications, anyone want to buy 49mL of UV protector?
The new horns are slightly bigger than the original, so I did a test fit to make sure there was enough room and there is enough clearance. I wondered if I was going to find the unused wiring tail on the drivers side, but no, they deleted that as well. No matter, the horns I had bought had standard spade connectors of course whereas the original(s) have special connectors for two very fine pins on the horns, so I made up a tail to go across the car from one to the other. The existing bracket was angled affair with a locating peg to ensure the horn was mounted at a given orientation, but the mounting 'bracket' (just a strip of metal with two holes) for fitting to an MGB was just the right size to put a bend at the end and mount the extra horn in the same orientation. Fortunately they hadn't deleted the mounting hole, which is used to mount something else as well, so came complete with bolt. Broke the habit of a lifetime and cut the original connector off for the existing horn, as I couldn't see how I was going to connect the new horns to it otherwise, those Scotchlock connectors being a bit iffy anyway, especially exposed to all the elements, and doubly so given the very small gauge of the horn wires. I soldered bullet connectors to the wires and assembled them with Vaseline, to aid assembly as well as give some protection against moisture.
Tested the horns before refitting the bumper and they have much more presence! By the way, test the horns before you start, you wouldn't want to go to all that effort and find that one didn't work! Loosely attached the bumper with just its top fixings, refitted the fog-light and temperature sensor connectors and tested the fog lights, then refitted the bumper. Final test of the horns and lights, and all done. I did wonder if the missing clips would result in any squeaks or rattles, but in fact one rattle which appeared to be coming from the front right corner seems to have vanished, in two drives of just a few miles anyway.
Key Fob May 2014
Did a quick Google and found a YouTube but it was for the older one, then found a description that was a bit cryptic. Also slightly concerned to read that it needs resynching afterwards, although that is apparently achieved by standing close to the car and pressing one of the buttons four times.
First step is to unlock the car! However you also need to open the door, as otherwise it will simply lock itself again after a few seconds.
Worked out how to slide the bottom cap off for fob, then split the two halves to extract the battery. Tried cleaning the contacts first but no go. Fitted a new battery, reassembled the two halves but not the end-cap, and went outside to try it. Tried the 'lock' button - no go. Tried it three or four more times - still no go. Starting to get a bit nervous then realised it had locked itself after being unlocked because I hadn't opened a door. Tried the unlock button and fortunately that worked.
I've had the car seven years and I've always needed to be close to the car to unlock it, which I've never really seen as an issue as I'm usually quite close to the car when getting in and out! The plippers that work over hundreds of yards are also a bit of a security liability as they make it so easy for someone finding the keys to discover which car they fit. And I don't usually need to be reminded where I've parked the car. With the new battery I move further and further away and it still responds, not yet discovered just how far it will work. I did momentarily ponder changing the battery in my every-day fob as well, but as both would have been from the same Pound Shop packet I don't want them both failing in days through faulty manufacture! So I opt to just open that up and clean the battery and fob contacts, and now that works over a longer range as well.
A couple of sources said once the battery has been removed press any of the keys 'to discharge the capacitor'. I didn't do that with the second fob and the first key press of that functioned as it should. I suspect not pressing a key to discharge the capacitor kept enough energy in the electronics to mean resynching the rolling codes wasn't required.
Low battery warning: Another source showed a section from the driver's handbook for the earlier rectangular fob stating that when the battery gets weak the indicator light on the dashboard flashes rapidly for 45 secs. However both of my oval fobs do that, including the one with the new battery, and reading the handbook with my car it says "... the alarm indicator light flashes (0.5 seconds on, 0.5 seconds off) for up to a maximum of 15 seconds or until the starter switch is turned on." But I've never noticed that even when I had to get close to the car before my 'every-day' fob would work. It also says another indication of a weak battery is "The alarm control unit only accepts every other operation of the handset lock and unlock buttons". Not specifically noticed that either, although perhaps when I've been on the limit, distance-wise, that's what it's been doing when I assumed it was simply down to me being close enough or not.
Idle Control Valve June 2012
I suspected a sticking idle control valve, which lets air in past the fully closed (when the throttle is released) butterfly valve, to electronically control the idle speed. I knew it was fairly accessible, but it is very accessible - right on top of the inlet tract and near the front with very little round it. Depress the collar on a vacuum pipe and remove the tube, remove the electrical connector to the stepper motor, then two hex socket screws are all that holds it onto the inlet tract, and you can carefully lift the valve from the main tract being careful not to rip the gasket.
Two passages on the bottom of the valve, with a plunger controlled by the stepper motor between them. Quite a bit of soot around the plunger whereas I was more expecting thick oil from the crankcase ventilation system. Two Torx screws hold the stepper motor to the valve, and the plunger comes out with the motor. Gave the valve body and the plunger a good spray with carb and fuel injector cleaner, which is highly pressurised so blasts muck off as well as the solvent dissolving it, and a wipe got things completely clean. Refitted the motor and plunger to the body, put a smear of Hermetite Red on the bottom of the valve (the gasket had remained on the main tract), and refitted the valve to the tract. Replaced the vacuum pipe and electrical connector, and started up. I made tiny movements to the throttle to close and open the valve, also put it in 5th and slowly let the clutch out with no throttle to make the valve open more than normal, and everything was exactly as expected. I've done a few miles in it since but it will need a few weeks without any reoccurrence of the sticking or stalling before I can say if it has fixed things or not.
I found some FM transmitters, including by chance one at Halfords (Sendai) which is very simple just having a socket for the player to plug into, two buttons to change the transmit frequency, and a display to show the frequency. Plugs straight into the cigar lighter socket (OK, 'auxiliary power supply socket'), and much cheaper than any of the others. I wondered how much range/signal strength it would have, internal radio aerials are notoriously poor as compared to external. Plugged it in, started the player playing, selected a frequency, and set the radio seeking for it. It found it OK, but there is quite a bit of interference with the player down by the cubby under ashtray and the wire coiled up, which is the most logical place to keep it. Then I found that if I moved the player further away from the transmitter i.e. straightened the wire out it was much better. So far so good. But it was all downhill after that as it started cutting out after a few minutes. Back to Halfords who suggested cleaning the power socket, which did seem to improve things - once - but then started playing up again. After a lot of faffing about where sometimes it would work OK for a while and sometimes not, in both the ZS and Vee, it was back to Halfords again but they didn't have any more in stock, and I thought it was worth trying another one so I hung on.
August 2008: After more bouts of it running OK for some time then cutting out again after a few minutes I went back to Halfords again, this time they did have another one on the shelf, and exchanged it without question. First drive of nearly half an hour and no cutting out but it is early days yet. However it also has much better signal quality and that is with the player and cable coiled up in the cubby, so I'm cautiously optimistic that the first one was faulty and this one will be OK. After a longer test next day and still fine I thought we were there. But the next day it kept cutting out after just a few seconds, so back to Halfords yet again, a refund, and good riddance. Next option was to get an MP3 radio, the cheapest of which I could find locally from the usual suspects was £60. I'd fitted one for my pal with the 'barn find' 78 GT which he sourced very cheaply so asked him where he got it. The good news was that it was under £40, the bad news was it was from Aldi who tend to get these bargains periodically but when they are gone that's it. However he said they had got them in again, so it was down to Aldi. Yes they had, in silver which probably matches the ZS fascia better than the black, but the only take cash or debit cards and I only had my credit card with me! So back home for the right card, back to Aldi for the radio, and back home again. Checked the connections at the back and it was a standard plug with the connections the same as the old radio, but the plug on the end of the aerial cable was the ISO very low profile right-angle, whereas the radio needed a long straight standard plug. So back to Halfords yet again to get an adapter. After that it was a matter of swapping the cages over (the new one not sliding in as far as the old but far enough) then removing a couple of the switches close by so I could hold the big in-line multi-way connector up into a recess above the radio with a screwdriver (the main slot isn't deep enough to accommodate the radio plus this large connector behind it) and push home. Everything works OK, and I'm sure it sounds better than the old one (Kenwood) which took a lot of fiddling with equaliser and bass, treble and middle controls to get sounding anything like decent. MP3 player plugs into the aux socket on the front, but you have to use the MP3 player controls. There are also sockets for SD card (1GB max, I need over 2GB) and USB flash drive (no limit given), the implication being that you can use the CD controls on MP3 files on a flash drive, so that is the next thing to investigate.
September 2008: And a 4GB proves just the ticket. It can plug directly into the front, and one that swivelled through 90 degrees would reduce the chance of it getting knocked and causing damage, but mine doesn't swivel. No matter, there was a USB extension cable with the radio, which doesn't stick out much, and allows the flash drive to be tucked into the cubby under the ashtray. Not only can you navigate both folders and files, but it displays the names while it is playing.
I made a template out of card drawing down the lower edge of the arch and across underneath, then back to encompass all three screws. Cut that out, then put a blob of paint on the head of each screw, carefully lined up the template with the arch, then pressed the template onto the head of each screw, which left a perfect imprint of where to make the holes. Then I could position the template over each arch (turning the template one way for one arch and over for the other) to get the amount of overlap I wanted, and scribed round the template for what needed to be cut off. The material is quite rigid plastic rather than rubber, and so was easy to cut with a jig-saw.
Removed each road wheel in turn, the three screws with washers, then fitted the flaps. Being thin there is still plenty of thread left to hold them and secure the body-kit and arch liners. Replacing the road-wheel I put a little copper-grease round the centre hole, as this is a snug fit to a boss on the hub, and you can get corrosion here which makes the wheel difficult to remove.
One year on it's due for an oil and filter change. Rather confused by the Mobil 1 sticker in the window but the specification is 10W/40 ACEA A2/A3 whereas the Mobil 1 viscosity is 0W/40. Turns out they were only paid to put the sticker in the window, not the oil in the engine! Wandering round Homebase while Bee was having her MOT I found some Castrol GTX 10W/40 they were selling off at half-price, so that was a result. Subsequently I did use Mobil 1, and even more subsequently it's gone back up to 5L and on offer so comparable to lesser products. Next problem was the filter. Halfords don't have the ZS (or ZT) listed in their customer quick reference cards only the ZR for some reason, and it isn't even listed on their computer, however it is listed online as HOF319. Following an enquiry on the BBS I found the MG Rover/XPart number was LPW100160, and an MG/Rover specialist only a few miles (S.A.S Autos) away had them at £7.50 and no VAT, so another result (Update May 2011: Part No. updated to LPW100161, not 100181 which is the smaller filter for the 1.4, and only £7 this time). I found references to Crosslands 2C2277 and Filtron OP580/6 equivalents but don't quote me. Another car spares place nearby had a Fram equivalent at half the price of the MG Rover, but since I found the pressure rise time with a Fram on my roadster was very poor compared to Volvo/Mann (and even Halfords and Champion), and some don't have a bypass valve so the filtration medium can burst on cold starts, I won't use them again. Oil Filter and many other part numbers at MG-Rover.org together with other spec and 'how to' info.
It will be due for a cambelt change next year and out of interest I asked the filter supplier how much - £700 ouch! But a neighbour knows people at Gaydon who worked on these engines and has offered to help, so I think I'll be taking him up on that (did it myself in the end, see here).
The Haynes manual shows where the filter, drain plug and gearbox level plugs are but as close-ups so it isn't easy to see where on the car they are. These pictures give a more general view and have the items arrowed. The filter and drain plug (15mm) are on the right-hand side near the back of the engine, the gearbox level plug on the left-hand side immediately behind the driveshaft. Mine is an R65 gearbox, the plug is slightly closer to the driveshaft on PG1 gearboxes it seems. Haynes says to remove the undershield, but it isn't necessary on my ZS180 at least, either side. The sump drain plug was very tight, I had to use my breaker bar. If you undo the final threads with your hand coming in from the side and above the bolt you can avoid the dreaded 'hot oil up the sleeve' syndrome. But the old oil squirts out quite fiercely in an arc to begin with landing a good 12" or so from a position vertically beneath the drain plug, I also got a small amount dropping vertically as well, so you need a large enough receptacle to collect both. Whilst newspapers will collect drips they won't be good enough to collect even the smaller vertical flow. Bear in mind the sump and filter holds 5.2 litres so make sure your receptacle is big enough. As the level lowers the arc lessens, eventually dropping vertically for the last trickle, so you need to be watching it to keep the receptacle under the flow(s), as well as watch out for any breezes blowing the smaller trickles around (newspaper is fine for catching these). Haynes says to renew the sump plug sealing washer, but they always say that, I never have with previous cars and I've never had a problem, so didn't lay one in. However on all my other cars they have been copper washers, this one looked like steel with a rubber insert sealing to the threads, so I think it advisable to replace and I will do so in future. However subsequent research showed this to be a mystery part that no one had ever seen on a ZS 180, although Halfords have something very similar for a Ford (I think). It should be an aluminium washer (ALU1403) but Halfords have the correct size, so I bought one for the second service. The filter came off easily enough with my chain wrench, which only just fitted between the filter and the part of the sump that is adjacent to it. Because the filter is angled oil leaks down the side while you are unscrewing it, which with latex gloves makes the filter very slippy and impossible to get a grip on. But the oil is hot so you do need gloves! Eventually I have the idea of wrapping a couple of turns of masking tape round the filter before I start, and that makes things much easier. It isn't really feasible to change the filter while the oil is still draining from the sump unlike my MGBs, so you have to wait until it is finished, refit and tighten the sump plug before doing so. A lot more oil comes out of the filter and filter head, so again the receptacle needs to be underneath. Mine was pretty full from the sump, so I emptied that into an old 5L oil can before removing the filter. With the old filter off and it and the oil out of the way get the new filter, lubricate the rubber ring with fresh oil (the books say, personally I use the oil just drained. Just use a smear, if you put too much on it might run down the side of the angled filter when fitted making you think the seal is leaking), screw it on to the filter head bearing in mind the ZS180 is at an angle and not vertical i.e. don't cross-thread it. When the rubber seal just touches the filter head use hand pressure to turn another 270 degrees or 3/4 turn. Double-check the sump plug is tight. Refill with 10W/40 ACEA A2 or A3 (ignore the Mobil 1 stickers everywhere). Fill to the Min mark, another litre should bring it up to the Max mark. Start the engine, immediately check underneath for any major leaks, check the oil light goes out (it will take longer than normal this first time) then spend longer underneath making sure there are no drips or leaks. Switch off, and after a few moments recheck the level, you will probably have to add a bit more to take account of what is now sitting in the filter.
Update May 2010: Time for the oil and filter change again. After discovering last year that my drain bucket only holds 5 litres and overflowed, this time I bought a 6 litre drain can, which made more mess than the overflowing bucket last time! The trouble is that the flow shoots out with such force, even with the oil filler cap still on (which makes no difference with this type of crankcase breather system as the restriction is between the crankcase and the inlet manifold, not between the crankcase and outside air as in the MGB), that it shot over the shallow sides of the drain pan. Even standing on large sheets of newspaper in a cardboard tray it escaped, fortunately the corner of the tray was just over the edge of the groundsheet I was lying on so stayed off the drive. The can must be lying completely flat and level or again it will overflow the sides, and the side you drain into bulges up so you have to press the middle down to get it to pour in through the bung hole, and there is always some left behind. I'll have to think of something else for next time, maybe building up the sides, or holding a 1-litre container with the bottom cut off in the flow, with its flexy nozzle sticking in the bung hole. The hanging oil filter is also a pain, being at an angle oil starts running down the side as soon as the seal comes off the seat, latex gloves won't grip it anymore, so you have to wait for that to finish draining before you can get some newspaper round it to get a grip and unscrew it the rest of the way, more oil running down, and up your sleeves if you aren't careful, and even after that when you finally remove the filter another cupful of oil spurts out of one of the ports in the filter head. Ended up dropping old filter and paper into the bucket, more mess to clear up. You can quite see why people bang a nail in the bottom first to fully drain it, but I wouldn't dare do that until I had started it undoing. I changed the rubber-cored sump-plug sealing washer for a plain alloy one last year, so that just went straight back on. After running the engine to check for leaks I noticed a little runnel of oil comes down the side of the new filter to form a small droplet on this and previous occasions, just the one, so probably just surplus oil round the top and not a leak.
August 2014 Checking the oil level: I say 'fill to the Min mark ...' and 'recheck the level' above, but it nowhere as simple as that compared to any other car I have had. For some time the erratic readings confused me - sometimes above the Max mark (strongly advised against in the handbook) and sometimes below, with no correlation to usage or topping-up, even when I followed the handbook advice of withdraw, wipe, reinsert, withdraw again, and check. Then I realised that because of the wavy tube and the wire dipstick, as I'm withdrawing it the indicator is depositing oil further up the tube. Then when I reinsert and withdraw again, the oil that has been deposited in the tube is being picked up by the top of the indicator and hence appearing above the Max mark.
So I can only check the oil after it has been standing some time, ideally overnight, and then only withdraw it once checking the level immediately. If it needs oil I would have the same problem, so going by the indicator I have to judge how much I need to add (nothing if it is more than half-way from Min to Max, 1/2 litre if it is between Min and half-way to Max, or 1 litre if it is below Max), add that amount to a 1 litre container that has graduations down the side, then empty all that into the engine. However. Having found the level about 1/4 the way from Min to Max, I added 0.6ml. Next day the level is off the top of the indicator! I hadn't run the engine after topping-up, but surely oil can't lodge at different levels in the engine until it is run, can it? But I run the engine for about a minute, switch off, leave it for about five hours, and now it is only about 1/8" above Max. A couple of people have suggested leaving the stick out overnight, then pushing it down, pulling it up and reading it then. But for that to make a difference the indicator would have to be trapping the oil above it, and seeing as how the indicator is less than half the diameter of the tube I can't see how that would happen. Nevertheless I pull it up a few inches (not quite the same thing I know) i.e. more than the length of the indicator and wedge it under a suitable bolt (or the bonnet will push it back down again) and will see what it is like in the morning.
For similar reasons I can't check it shortly after running the engine either. For oil changes I have to add the bulk then a litre at a time until it appears on the indicator, then use that level to judge how much extra I need to raise it to Max, and add that amount with my graduated 1 litre container. This is all before running the engine for the first time, checking the oil light goes out, and for leaks. Then I have the problem of not knowing how much extra I need to replace what has gone into the new filter, and anywhere else it might have drained out of, until it has been left several hours or overnight again. A pain.
May 2015: Oil and filter time again, and this time I decide to measure how much comes out. The book says 5.2L for an oil and filter change, so I put 4L of the old oil in one empty oil container (4L was the highest mark even though it is a 5L container) and got another 2L in another oil container - i.e. 6L! So I emptied a fresh container (5L) of Mobil 2000 in first, then added another Litre from a part used container. Dip-stick initially showed up to the Max mark, but I'll have to wait for it all to drain down before I can get a better idea.
With the gearbox level plug (17mm, drain plug is 3/8" square drive!) undone use a mirror and torch to check the level. Mine is down a bit, I didn't get any in to begin with, so I shall have to get some then get down and under again to top-up. Use 70W/80 gear oil in the R65 gearbox, should be easy enough to get hold of. The PG1 specifies MTF 94 and gives it a viscosity of 10W/40, which makes it sound like engine oil but I don't think it is so don't use it instead. There is a lot of discussion on various boards (search Google with 'MTF94 oil') and it seems a bit specialist, some people reckon it is vegetable oil and not mineral (which is why you shouldn't use engine oil even of the same viscosity), ATF either isn't up to the job or makes for stiff changes when cold, and so on.
Followed the instructions to the letter cleaning the glass with meths, then wetting it, before attaching the film. This helps it slide into position as well as stick well afterwards. The only tricky bit was cutting out round the mirror, which isn't perfect, but doesn't really notice. The film consists of clear plastic film covered in dots, which start off at the top being more do than space, then the dots get smaller towards the bottom edge, to give a graduated effect. Makes a noticeable difference, but if anything a deeper or double strip probably wouldn't be too much, it still dazzles more than the V8.
Variable Intake System Added February 2009
Wheels and Tyres Added January 2011
Wheels: As mentioned above the wheels are horribly easy to kerb, being wider than the tyres. Four years down the road (so to speak) and not having kerbed them for a couple of years or more, I was just thinking I might get them refurbished when blow me if I didn't clout one of them again, so that idea goes on the back-burner. Another problem has been staining of the painted surface particularly at the front from brake dust, but also the rear, being impossible to shift the stains which look like deep scratches with normal hose brush, sponge, cloth, or leather. I did tentatively try a wet green fibrous pan scourer (which is excellent for getting staining of UPVC window frames, facias etc.) but even tentative rubbing immediately showed some surface scratching so that was out. Then in Halfords I noticed this brake dust remover which used wet removes the staining completely, even in the angles between the spokes and the rim, very easily and without any damage. It is perfect for the ZS spokes, and although it started to look a little ratty quite quickly at £4 you can afford to get one every year, and in fact it hasn't deteriorated any further and is still working well 2 or 3 years later. There is a 'premium' version at £5, and no less than 11 wheel brushes altogether from £3.50 to £13, but this one looks the best for getting in between the ZS spokes in the narrow space at the hub.
Tyres: The ZS has always been noisier than I would have expected (good job I'm used to MGBs) in the shape of tyre/road noise more than wind noise, and almost to the point that I wondered if it was a wheel bearing growling. But first I replaced the front tyres in mid-2010 (normal wear) then I had to replace the rears (moved to the fronts when the fronts were replaced) when there was still some life left in them. The problem is the ZS rims don't always give a good seal, and enthusiastic cornering can deflate them. They are so low profile that I've not noticed any change in handling even when completely flat, unlike the MGB which is immediately obvious even when it is a rear. The trouble is that driving them flat knackers them, putting splits in the side-wall, and when I had them removed to seal the rims one of them was full of rubber crumb which had been eroded from the inside of the sidewall. Nothing else but to replace the pair, which was annoying as even though the same place would have done the fitting I could have got a better deal ordering online than just turning up. However I immediately noticed with four new tyres (Avon on the rear, Coopers said to be made by Avon on the front) it seems noticeably quieter, and the noise I thought could be a wheel bearing has gone. The old tyres were Federal all round and I was wondering whether there was a connection with MG Rover (even though the car has done 35k!) so Googled 'MG Rover Federal' and blow me if I didn't land on an MG-Rover.org posting about Federals warping when they get hot and it sounds like a wheel bearing going! The other thing is that in the extended period of ice and snow in December the ZS performed very well, virtually no wheel spinning or ABS despite travelling from Solihull to Cambridge just hours after several inches of snow at each end. By contrast I saw some FWD cars struggling on barely any incline, and RWD cars stood no chance, being stuck in my road with a slight incline either end for the duration!
Spare Wheel Added November 2012 After having owned the car five years I thought I'd better check the spare tyre pressure. Certainly the jack has never been used (still in its cellophane wrapping) and I very much doubt the spare has been out either. In the end it took me over an hour! I could just about move the clamp back and fore, but even with releasing fluid it got so far then I couldn't undo it any more. Good job I was at home and not at the roadside with a puncture, as I had to use various tools to grip the clamp hard enough to be able to unwind it the rest of the way, and it had to be forced all of that way. Just rust on the threads, even though there was no sign of water in the well (so to speak!). Once out I had to clean up both threads with a tap and die before it would move freely, then put copper grease on it for good measure.