[TR] TR4A - Fuel on top of fuel pump

Randall TR3driver at ca.rr.com
Sun Dec 11 19:16:37 MST 2011


> My only theory is that the fuel is being drawn-up, against 
> the force of
> gravity, through the holes that secure the circular top of 
> the pump, to the
> main body.

That joint is actually under pressure from inside.  For some time after
shutting the car off, it will be the full 2-4 psi output pressure of the
pump; but the tank is higher than the pump so even once the pressure has
bled (or leaked) away, there will still be enough to make it weep.

Might well be the diaphragm dissolving, if you haven't replaced it
relatively recently.  The originals will definitely not stand up to
oxygenated fuel.

If that is the case though, I'd suggest replacing it sooner rather than
later.  If someone left out the shaft seal or it doesn't seal very well any
more, a leaking diaphragm can dump fuel into the crankcase.

-- Randall  


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