[T3] FI help needed

Jim Adney jadney at vwtype3.org
Sun Nov 1 08:33:39 PST 2015


On 31 Oct 2015 at 21:48, B Fye wrote:

> My OEM fuel pump is loosing much fuel from the o-rings by the oulet end.
> Are they supposed to be flat?  Also, is there a part number for them?  I
> need to order a pair.  The pump works great, just leaks way too much!

Those O-rings are originally round, but they get flattened with age. 
I rebuild a LOT of those pumps, and I replace those O-rings as a 
matter of course, but I don't think I have EVER seen a leak there. 
Are you sure it's not coming from the little silver cap on the relief 
valve? That cap sometimes corrodes thru and that's where the leak is. 
leaks around the electrical connector or the motor housing are also 
rather common, but those tend to happen most often on pumps that have 
dried out. 

Drying out allows the O-rings to shrink so they no longer seal. If 
this is the case with this pump, it MAY seal again if the O-rings are 
allowed to soak in gas for a few days and swell back up.

Rebuilding your pump will cost $75 plus return shipping if the motor 
runs and there are no leaks at the electrical connector or the motor 
housing. This repair fixes the O-rings, the relief valve cap, and the 
relief valve piston (which is starting to fail on all our pumps at 
this age) and is all that most pumps require.  

If I have to take the motor portion apart to replace the other 2 
O-rings, the price goes up to $125, plus return shipping. 

Return shipping would be $18 in either case.

I prefer rebuilding the OG Bosch pumps to replacement with a modern 
pump, because it means that you don't have to re-plumb the fuel 
lines, move the pump to a different location, and cut off the 
original electrical connector. If you just need the basic pump head 
rebuild, the cost is the same as the aftermarket pump.

Once rebuilt, the pump should last as long as it did the first time 
around, as long as you have done something to repair your cracked 
overflow hose. Most of the pumps I rebuild have suffered from some 
amount of abuse from water and dirt that came in thru those cracks. 
Water and dirt in your system will damage any pump you put in there, 
as well as the gas tank and all other parts of the FI (or carb) 
system.

-- 
*******************************
Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
*******************************



More information about the type3-vwtype3.org mailing list