Fuel pump leak

[RedLightBrew]

Fuel pump spitting a little fuel out of the hole in the middle of the top. What's up?

[boatbob2]

Your fuel pump diaphram is bad (cracked,Hole or just plain worn out) time to change the pump, ,maybe an electric pump from RAFEE,would be better...

[RedLightBrew]

Thanks for the reply. I was afraid of that. I'm going to stick with a mechanical pump. Ordered one from Rafee.

[bbodie52]

Try not to run the car with the faulty fuel pump diaphragm. A leaking diaphragm can allow fuel to leak downward too, into the crank case and diluting the oil with gasoline. A bad leak can flood the crankcase with gasoline and gasoline fumes, and potentially cause a fire or explosion hazard, as well as potentially damaging the engine due to diluted oil and a lack of lubricating properties!

I've included the section on the Corvair fuel pump from the 1965 Chassis Shop Manual, plus a link to some good information on the Corvair Underground Web site.

1965 Corvair Chassis Shop Manual - Section 6m - Fuel Pump.PDF

1965 Corvair Chassis Shop Manual - Fuel Pump

(408.24 KiB) Downloaded 133 times

Let's Talk About Corvair FUEL PUMPS
http://www.corvairunderground.com/fuelpump.htm

Pictures below show the internal components of the Corvair Fuel Pump.

[RedLightBrew]

Took old fuel pump off today. Ready for replacement to arrive. Uneventful so far. Also, look in the 1st and 3rd pictures. There's a grease fitting. What is supposed to be there? or Why is there a grease fitting there? Isn't there supposed to be a sensor of some kind there?

[bbodie52]

That grease fitting is occupying the location normally used by the oil pressure sending unit. I can only assume that sometime in the Corvair's past it may have developed a leaking sending unit, or the sending unit may have been lost. To fill the hole, the "mechanic" must have discovered that a grease fitting had the same thread size, so the grease fitting became a plug.

A new replacement sending unit is available at Clark's Corvair Parts for $6.15
Part number C484: OIL PRESSURE SWITCH-THIS IS NOT TEMP!!!! SPECIAL SOCKET=C5274 (MAKES EASIER)
http://www.corvair.com/user-cgi/catalog ... nd_page=11

The Corvair cylinder head Temperature Warning Light Switch and Oil Pressure Warning Light Switch are wired together, and then to the instrument cluster warning light. The engine schematic is shown below, along with the switch location and a picture of the switch itself.

[reedha]

i have a 64 rampside and the fuel pump was leaking about a drop every 10 seconds this morning, coming from what appears to be a vent hole, gas all over the driveway. i went and read up on leaks and found that , among other things, some people had started the car up and the leak disappeared never to return...so that what i did and thats what happened! leak stopped cold....lucky for me that worked so far today and i have a theory. is it possible that the mechanical pump can rest in a very specific one in a million position to allow such a leak? or is the pushrod position ( up or down) dictating 50 -50 whether there is a leak or not?
obviously if there is ever a leak again it will be replaced...thanks

[Grandpacorvair]

Nice truck..

FWIW if MY fuel pump leaked....even once, it would be gone (unless the leak was because of loose cover screws)....a leak indicates a problem. As stated above a leak can go into the engine, contaminating the oil. Bad things can happen. JMHO.....

In the end, I got tired of fuel pump failures and switched to an electric pump, installing the 'dummy' pass thru core in my pump housing.

Kerry