Pump Refurb No.2 - with problems
by Michael Beswick

In June 2014 I rebuilt my points type SU pump with the Burlen rebuild kit. In February 2015 I had a significant leak. On investigation the washer below the diaphragm in the fuel smoothing cavity (under the "top hat" cover) was badly distorted as was the cork washer under the inlet smoothing cavity cover (the one with the single bolt through the middle). Replacement parts seemed much the same type/quality but the O ring which fitted below the top hat cover was too "fat" to allow the cover to sit flush. The cover is intended to nip down the O ring but this was not going to be nipped!

Replaced cork washer badly distorted as well as being smaller than the original on the left:
2014 diaphragm washer distorted as if from fuel:
2009 hose showing no sign of deterioration:

After much to-ing and fro-ing the pump was returned and rebuilt by Burlen. It has now been re-fitted. Whilst the whole fuel system was empty I decided to replace the fuel hoses with ethanol resistant hose. Specifically the braided short piece from pump to fuel line (fitted in 2009) and the braided piece along the bulkhead -replaced in 2013. I am very suspicious of braided hoses as I suspect that more attention is paid to the appearance as opposed to the actual hose. The car is chrome bumper so the pump is by the rhs rear wheel.

This Gates 'Barricade' seems to be the Holy Grail but Gates (UK) only sell to their main distributor -Ferrari Piston Services, who in turn sell to motor factors from whom one could purchase. It is 15 or 25 foot rolls......As soon as the average motor factor realises it is fuel hose they turn off from the specified hose and talk about having plenty of stock...... However Codan make a similar product that appears more widely available. Beware there is a huge amount of mis-information out there. Many suppliers quote lots of different county's specification standards. Different Standards refer to porosity and then abrasion, and so on. Porosity is not necessarily related to the ability to withstand ethanol! I managed to obtain hose to SAE J30 R9 which should be resistant to up to 15% ethanol.

Fitting is relatively simple but be aware that 5/16 (8mm) hose is needed at the fuel pump to fuel line end. I still have the piece at the bulkhead to do. It has a screw fitting at one end and I hope a spigot that I suspect will need 1/4 " hose (to then connect to the fuel filter and subsequently filter to carb(s). I actually bought a new banjo for the pump end (BHH 1940 supersedes AUB846) but subsequently managed to remove the banjo from the discarded braided hose. I hope to do the same with the bulkhead screw fitting.

So did ethanol cause the problem? There has been plenty of chatter about ethanol, but more about what it is capable of as opposed to what it has actually done. I have not heard of a single documented case where it can be shown to be the cause. However the parts in the pump had deteriorated: the washer looked similar to the effect of petrol on a latex glove - wrinkled and distorted. Burlen replaced the cork washer with the new "material and shape" washer, which rather implies something was not quite right. However it could just be a bad batch of replacement parts. There have also been instances where new parts do not fit the older body- such as my O ring in the old body. My rebuilt pump needed a new body as a screw thread had worn, which avoided the problem (conveniently?).

So I examined the hose that I removed (the braided one), which showed no appreciable deterioration of the inner wall.

Ethanol is reputed to attack almost everything, to the extent we may as well dump the cars and buy a bike; but in the meantime it would seem to be worth doing only if you have cause to replace enough hose/pipework to require draining the tank. (Or lowering the level if you are fortunate to have the pump mounted higher in the boot!) I remain suspicious of braided hoses and feel that replacing rubber hoses every five years is probably sensible.