C1 and C2 Fuel Pump Question

[Christopher R.]

The rebuilt 4656 AC Delco fuel pump in my '62 has leaked every Spring for the past 3 years upon starting the car after its 5 month Winter layover. Scares the heck out of me. I hate raw gasoline spilling onto hot exhaust pipes inside my tiny garage. By the time I get to check the pump, there's gas everywhere. Hard to see where exactly it's leaking. But it seems to be from the lower portion of the pump. The one held on by the 2 cap screws.

Every Spring, I overtighten all 10 of the cap screws round the top portion of the pump; the gas line fittings; and, the 2 cap screws on the bottom. The leaking stops. The screws are not all that loose to begin with. But they can stand a little tightening. Don't know what the torque values there are, but I suspect I'm overtightening them. But it works.

The gasket on the bottom portion of the pump is something that is black and contains yellow lines running through it. The pump is stamped "4656", but the stamping looks suspect. It is embossed "AC" where it should be.

I leave gas in the line over the Winter. But there is a shut-off petcock in line. So if the gas were to evaporate in that chamber, it would not be replenished.

Thing is, I don't trust the pump now. Has anyone else had this problem with a C1 or C2 fuel pump?

[James F.]

Re: C1 and C2 Fuel Pump Question

Chris,
Conventional wisdom tells me to rebuild or have the pump rebuilt! Were it me, I certainly wouldn't put up with this for three years! Regards,

[Mike E.]

Re: C1 and C2 Fuel Pump Question

I've had dozens with 4656's or their direct replacement, 4657, and have never had the same problem--and have lived in Wisconsin and southern California, so climate should not be a factor.

[Mike M.]

Re: C1 and C2 Fuel Pump Question

perhaps the pump was rebuilt with an inferior, generic, slant-eyed diaphram . why not pull it amd rebuild it? kits are about 20 bucks . good luck and pray the gasoline god is smiling your way. mike

[Christopher R.]

Re: C1 and C2 Fuel Pump Question

Thanks, Mike and Mike and Jim. You gave the real answer to the question I didn't ask - Is this condition common? It's clearly not. Replacement fuel pump will be done this Spring.

[Don Izzo]

Re: C1 and C2 Fuel Pump Question

I had a brother who burned up more Corvettes back in the mid 60's than any one I knew! I have been a volunteer Firefighter in my small home town (ex-captain)for over 10 years and have responded to a few reported Car fires that turned out to be structure fires when it was discovered that the car was actually burning inside the garage! Get that pump out and rebuilt NOW or park your car outside! Failing to do so is the same as having no battery in your smoke detector. Just plain stupid! PS liquid gas does not burn, it is the vapors or fumes given off by the gas as it rapidly evaporates! You get enough gas fumes in your garage and you can create an explosive atmosphere, cranking on the ignition key can provide an ignition source and your garage (home) goes boom! Ever tried to put out a fiberglass fire? not an easy job even with a 1+ 3/4" fire hose.

Don
Ex- captain, Montrose F.D.
N.Y.

[Christopher R.]

Re: C1 and C2 Fuel Pump Question

Thanks, Don. This is what concerned me. I'll take your advice and replace the pump. Life's too short to worry about stuff like this.