[Abs-Zero]

 

Current Project - 1947 Vauxhall 10

22-23 October 2008 - Fuel Pump rebuild

Having had some excitement getting it started the other week, I wanted to start on getting it so that it runs properly.  That meant checking and replacing the flexible fuel line between the body and fuel pump, rebuilding the fuel pump, draining some 40 year old petrol out of the tank and putting some fresh fuel in.  That's the quick version.

I had a lucky spot on eBay, where a UK seller had a rebuild kit for my particular A.C. fuel pump for sale at £10 (Buy It Now).  Needless to say I bought that as it came with all of the parts and gaskets needed to completely refurbish the pump.  The five screws basically clamp the diaphragm in place, once undone it could be seen that the original diaphragm could have been reused, as it was still reasonably supple, although clearly delaminating in the region that moves.  More out of interest, I elected to completely strip the pump down to all its constituent parts and clean everything carefully.  Predictably the inside of the pump was dry, but on the whole very clean.  The only dirt to be removed was from the sediment trap, which had a light coating of reddish brown dust, which looked like soil.  After reassembly (noting that the diaphragm should be clamped only while the actuating arm is fully depressed) the pump made an encouraging low pitched squeak/whoosh noise when actuated, together with generating obvious suction at the input.

Next came the fuel pipe, which was (as predicted) perished within.  It's an interesting design, with brass ends, which screw into the ends of the fuel hose, which is a rubber item with a steel wire spiral wound inside to provide the thread.  Externally it was sheathed in steel braid, but predictably, the rubber had perished and been dissolved by the fuel.  Not having any of the original pipe to re-make the pipe, the obvious option was to use modern reinforced rubber fuel pipe fitted onto the end connections.  Mental note to self - fit some Jubilee clips before MOT.  It doesn't leak but will if left indefinitely and would deserve to fail the test.

Next came a quick investigation of the fuel tank.  Not knowing what was inside (suspecting it would be dry) I passed a length of rubber pipe down through the fuel filler tube (no anti-syphon passages then) and wiggled it around inside the tank.  Pulling it out it was evident that there was some 40 year old petrol inside, which without its more volatile compounds smelt pretty awful.  I therefore removed the drain plug in the bottom of the tank and collected the reddish brown liquid that ran freely out, before pouring some fresh fuel in and flushing the rest out.  Very little sediment actually came out and so I suspect that an in-line fuel filter fitted into the flexible pipe I've just replaced would more than likely provide adequate assurance of clean fuel entering the carburettor.

So, had I done enough?

The most interesting bit perhaps was whether the pump would successfully pull fuel up from the tank while it was itself internally dry.  Cranking the engine over continuously wasn't going to be an option, not least because the poor starter motor wouldn't appreciate it, and partly because I doubt the battery would stand up to it for long.  Instead, Plan B came into action and the engine was (after much messing around and lack of coordination) started using Easy Start squirted down into the carburettor.  Guess who had just poured all of the available petrol into the tank?  Eventually the engine would run for a few moments as before and die away, but after opening the throttle slightly I persuaded it to run for longer, pulsing the Easy Start stream into the carburettor.  Then, fearing for the heat generated by the engine (there is still no coolant in the system) I stopped squirting Easy Start.  The engine carried on...

So now I can switch the ignition on, press the starter button and start the engine.  The throttle seems to be responsive (although sticky) and I obviously had to switch off and let it cool down before any damage was caused.  Enough for today!

Photos coming soon.

 

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Last review was Friday, 31 October 2008