[TR] Fuel pump oil seal

Randall tr3driver at ca.rr.com
Wed Mar 19 15:03:14 MST 2008


> Any experiences with or without this seal?

Angelo, I believe the seal serves two purposes.  The first purpose is
probably no longer necessary, that of keeping crankcase fumes away from the
pump diaphragm.  Modern diaphragms now have nitrile rubber in them (in order
to withstand modern fuels, which the original diaphragms would not), which
also makes them more resistant to crankcase fumes.

The second purpose is not all that critical either; when the diaphragm does
develop a leak, the seal helps keep the leaking fuel out of the crankcase
(and dripping from the weep hole where it will hopefully be noticed).

I found an old brake rubber in the junk bin that made an approximation of
the seal, and after a few tries to find a diaphragm compatible with
"reformulated" gasoline, the result lasted quite well.

Randall


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