Fuel Pump Leaks

[colonel]

This may be a dumb question. I moved my 74 2.0 fuel pump from the rear of the car to the front. All hoses and filter are installed. I attached the fuel pump, connected the wires, put a small amount of fuel in the tank and turned the key. The pump whirred and started leaking, it seemed, around the top cover near the R line. The hoses were tight. It seemed that I had the polarity of the wires wrong. Could that have been the leaking problem? Was the pump running in reverse? I removed the pump thinking that it was bad. Now I'm thinking that the pump is good and I should reinstall with the correct polarity. Any comments other than I'm a dummy messing up the polarity?

Thanks,
Bob Soldani

[porschetub]

Originally Posted by colonel

This may be a dumb question. I moved my 74 2.0 fuel pump from the rear of the car to the front. All hoses and filter are installed. I attached the fuel pump, connected the wires, put a small amount of fuel in the tank and turned the key. The pump whirred and started leaking, it seemed, around the top cover near the R line. The hoses were tight. It seemed that I had the polarity of the wires wrong. Could that have been the leaking problem? Was the pump running in reverse? I removed the pump thinking that it was bad. Now I'm thinking that the pump is good and I should reinstall with the correct polarity. Any comments other than I'm a dummy messing up the polarity?

Thanks,
Bob Soldani

Bob,more info needed on your install?

[colonel]

Big boo boo! Turns out that I had the correct polarity for the wires. My problem was that I mixed up two of the fuel lines. After replacing the fuel tank, all fuel lines, filter etc, etc, I noticed that I had reversed the input input (Suction side of fuel pump) with the output (Discharge side of fuel pump). I changed both lines, added fuel and after about 5 to 10 seconds of cranking, the engine fired and ran very smoothly after an 8 year sleep. Boy was I stupid!

Bob Soldani

[TheCabinetmaker]

Sounds like the pump was leaking at the pumps seam, which indicates a failure of the rubber seal. these stock pumps do leak if left to dry out after long term exposure to gas. the rubber seal swells with gasoline, then after long term exposure, if the seal dries out, it shrinks, causing a leak.
Could it be the pump got dried out during the moving procedure? I have had good running pumps, get left out and then they leak. I was able to restore a leaky pump by soaking in fuel for a few days. but that just was not good enough for me, as I doubt the original compression of the rubber seal is completely restored by re-soaking in fuel. although my pump stopped leaking, I decided to not risk a compromised seal on the pump, and I instead bought a new pump.

I don't see how mixing up the hoses would cause a pump to leak, maybe that is possible, however if that is the case, that means the seal has been compromised, gas was getting past it.

id replace the pump if it was my car, don't trust it.

[colonel]

Thanks Cabinetmaker. Good suggestion on replacing the pump. After correcting the fuel lines, the car started and I noticed that the pump was weeping fuel. Seems the O-ring seals were dried out and caused fuel to seep through. After running for 10 minutes or so, the fuel weeping seemed to stop which probably indicates that the fuel actually swelled the O-ring and stopped the leaking. Probably should replace the pump.

[Tobra]

The fuel pump they use on the '75-'76 cars is the same one they used on the VW Bus and Superbeetles, I think they sell that one here actually.