1.6 TD Fuel Pump Throttle Shaft Seal

[Doug]

So I pulled that crazy spring affair off the top hoping that there was a simple seal to change out. I am looking at a copper bushing that I assume is pressed in the top cover of the pump. How do you get access to the seal? I was told that it was an O ring waiting to be picked out but I'll be damned if I can figure out how to get at it leave alone see it! Any assistance is appreciated. As an aside the pump top nose  where the copper bushing is pressed in has been worn by the spring I assume to the point that it looks like a tiny edge of steel? is showing??? WTF now? JB weld??

[Vincent Waldon]

The o-ring is on the throttle shaft... some pictures here:


http://www.vwdiesel.net/phpBB/viewtopic.php?t=3241&highlight=throttle+shaft+seal

[Doug]

Thanks, Vince, I figured as much but was scratching my head about this idea that it could be replaced without pulling the top off the pump. that came from a so-called knowledgeable source too. Now for another question to you ar anyone else who knows, does the aneroid have to be removed before pulling the top of the pump or can it be left in place without disassembling lifting the whole works as a unit? None of the sources that I have checked seem to give any details.

[Vincent Waldon]

Thanks, Vince, I figured as much but was scratching my head about this idea that it could be replaced without pulling the top off the pump. that came from a so-called knowledgeable source too. Now for another question to you ar anyone else who knows, does the aneroid have to be removed before pulling the top of the pump or can it be left in place without disassembling lifting the whole works as a unit? None of the sources that I have checked seem to give any details.

Yeah, until you've done it once or twice it is a bit of a mystery... even with the exploded diagrams.

The lid comes off with the aneroid attached just fine.  If the throttle bushing is actually worn pressing out the old one and pressing in the new one are a bit more of a pain, but other than that its business as usual.

[Doug]

Thanks again, Vince. Well, I did pull the lid off the pump replacing the cold start shaft O-ring and the throttle shaft O-ring as well as the lid formed ring last night. Thank heavens that I have finally got a heated shop to work in! Today I have run it about a 100 km and while it is no longer leaking at the shafts mentioned and the distributor head O-ring was done a couple of weeks ago, it is still leaking fuel somewhere off the backside where I cannot see clearly. Do you know if there is another shaft or plug that could be leaking in that vicinity? I realise that if there is I will probably have to pull the pump. Damn!

[Vincent Waldon]

Another "usual suspect" in the leak department is the two o-rings on the cold-start lever assembly, which is in fact at the back of the pump and so sadly the pump will have to come out.

You can see why many of us, when detecting *any* leak, simply heave a sigh, roll our eyes heavenward, and pull the pump straight away for a full reseal.  It's all a big chain that breaks at the weakest link... and as you replace seals you put more pressure on the next weakest link.

The good news is that the cold start o-rings are cheap and dead simple to replace... much much less involved than the throttle shaft.  Two screws and the assembly comes off, one more screw and the shaft comes off the assembly.  5 minutes otta do it... once you get the pump out !!


Vince

[Doug]

Again, thanks, Vince. I take it that this must be the lower pivot point of the cold start mechanism? It has been difficult to find a really good diagram of this pump. They all seem to be too small and I can't figure out how to get them bigger. I did the upper shaft that pivots through the lid of the pump but it only had one O-ring. Sadly I managed to damage the hook that holds the spring on that one as it was partly seized in the pivot bore of the lid. Luckily I had an old pump laying around that I was able to rob for the shaft/hook (even if it was not exactly the same) for a quick turn around.

[carrizog60]

sometimes the copper busching needs to be replaced as it wears down and could not assure a good seal to the oring.
mine did that...