The Stovebolt Site Forums The Shop Area Engine Shop Durability of aftermarket fuel pumps

I replaced the original fuel pump with a new glass top one about 4 years ago. Today I noticed it was spitting gas at the base. It left a trail out of the garage. I reseated the glass bowl but it apparently was leaking below that. I drove it several hundred yards and back in the garage and it wasn't leaking. What gives? Too much pressure? Is it the ethanol?

Anyway, what kind of life can one expect to get out of the current batch of pumps? I've only ran this one about 200 miles in 4 years.

I had a new replacement fuel pump and it ended up leaking oil out out of the pivot, just like the one I replaced. I replaced it with a new dual action one with an all metal body and for the first few days it leaked gas at the joint. Somehow the gasket material has swelled and it doesn't leak anynore.

When it was leaking it was dribbling so you couldn't tell exactly where from. At one point it had a good burst or stream coming from where the body meets the base where all the screws are. What kind of pressure do these pumps generate?

They are usually around 3 psi. My 47 manual gives a range of 3.5 to 6.5 but the later manuals have the top figure less than that.

Well I got around to replacing the sporadic leaking pump with a different one. The new one is showing the same symptoms. With a mirror I can see it's leaking under the seam by the screws. Now I wonder if my oil is contaminated. Anyway after initial install and a quick drive no leaks. Then I went to put it away and notice it leaking. The lines are clear and it has 2 inline filters, one before and one after. Would the one at the gas tank interfere with suction/pressure? I guess I'll order up another pump to be safe.

Have you tried tightening the screws that hold the pump housings together? If it's leaking where the diaphragm is sandwiched between the two halves of the housing, which is what your description seems to indicate, a quick tweak on the housing screws might be all that's required. Try the simple fix first!
Jerry

Will do. You know, I did that on the first one with no luck but haven't tried it with this one. I'll admit that this current pump is an older one that came off a running engine so it may have its issues. I just find it ironic that the symptoms are the same.

Just to be safe I placed an order for an extra pump. Not a traditional glass bowl type though. Apparently getting pretty hard to find at the FLAPS now.

I found that the new pumps leak oil after a while at the pivot. I have also seen the gas leaking at the diaphram joint. Toghtening the screws was somewhat helpful. The gas seemd to swell the material and it didn't leak until startup the following spring.

I have seen a lot of aftermarket fuel pumps leak with E10. I think the best way to keep gas out of your oil is use a Facet electric fuel pump and just block off the mechanical pump. Cletis did a pretty neat job of installing an electric pump and making it look like the old mechanical one is still doing something.

I have had problems with a fuel pump for my '39 Chevy, so one day at my local GM dealer I asked the parts man if he would check his parts list for the original fuel pump number and he found it still on the list and I had a new one in 2 days. Works great and was close to price quoted by local NAPA store. It differs only at the top(metal top, not a glass bowl)
Stan