TC: AC mechanical fuel pump oil leak

[BDA]

Here is the information on the Facet cube pumps: https://facet-purolator.com/specifications/

I would suggest that 40105 or 40178 would be good choices.

[Fotog]

Thanks, BDA.  That's what I looked at a year ago.  Maybe I could be satisfied with one of the 2-3.5 psi models that are good for 15 GPH. 

-V

[BDA]

Yes. I think the 40178 is the one you want then. The difference between pumps of the same pressure and flow are usually trivial wire ends differences but you should check them out anyway to make sure you get what you want.

[Fotog]

The good news is... (drum roll...) that going back to the original question I posed- can I just plug the vent hole on the old original AC fuel pump that was re-built without the oil seal?...-  I talked myself into the YES answer.  That is, I don't see why not.  So I cleaned and abraded it and put a little dab of thickened epoxy over the vent hole.  The next day I drove the car, and the leak is GONE!  Hot diggity!  So nice to not leave a 3-inch or more oil splotch after each drive.

Amazing how excited one can get about a simple little thing.

This doesn't mean that I won't buy a new fuel pump, but it is a huge and satisfying improvement and it confirms that the majority of my dripping problem was due to the pump.

Vince

[jbcollier]

Sorry, not a good idea.  The vent hole is needed for several reasons.  First and foremost is to vent air that is displaced as the pump diaphragm goes up and down.  Without the vent hole it can suck oil up and under the diaphragm which can cause the diaphragm travel to be restricted and the diaphragm to tear.  This would allow neat fuel to flow into your oil.

These chaps have the oil seals you are looking for:

https://www.s-v-c.co.uk/categories/stafford-vehicle-components-fuel-system-components-repair-components-for-ac-fuel-pumps

Please, repair it correctly either by fitting a new seal or an electric pump.

(edited to correct link)

[Fotog]

Ok.  I hear you.  I had concluded (rightly or wrongly) that without the oil seal between the crankcase and the diaphragm there really wasn't the need for a vent.  That the volume of air displaced by operation of the diaphragm was minimal in comparison with the volume of air in the crankcase, but the vent was needed when the oil seal was in place and the diaphragm was displacing the air trapped between it and the seal.

For a while there it seemed that nobody that I could find supplied a rebuild kit for the pump that included the oil seal. 

Thanks for searching out that source for me.  I'll probably still plan to put in an electric pump; I just need to think it through a bit- the mechanical connections, where and how to mount, etc.

-V

[jbcollier]

It's a case of "probably" you'd be ok.  Myself, I don't like to drive cars with built-in worries.  There's already enough to occupy one's mind just by driving a hard-to-see, tiny, fragile car.

[Pfreen]

I think it will work as you describe, but if the diaphragm ever leaks, you will fill the crankcase with gasoline.

Not a good idea.  Oil dilution and explosion possibilities are the bad things that can happen.

[Fotog]

I'm with you guys.  But it was an interesting experiment to determine that it was indeed my major source of oil leakage.  I'll get a new pump on order.

V