Leaking 4657 fuel pump

[John D.]

Having problems with a minor fuel pump leak on my 63. I think I know what the problem is but here goes. Right before the Seven Springs regional we were cleaning up the chassis and noticed the pump was ouzing a lot of fuel around the bottom round magnesium plate that is held on with two screws.
So I took the mag cover or plate off. Sanded it flat on my surface plate. Then I used another new repro rubber one piece gasket. Noticed that the screws were a little long holding the cover on. SO I used another pump for parts and put the correct blackened fillister screws on. Correct length.
Started the car up and no leaks. Was relieved. Well now the thing is damp again. Slight drip or stain on cardboard under the car. Still has an issue. Running 100LL Aviation fuel. Do you suppose this fuel is interacting with the repro rubber gasket? The gasket I removed was repro black rubber and it seemed to be of the wrong material. Didn't feel right? I said to my friend look at this material. Today my friend and I were talking as to why the pump still has a minor leak. Your thoughts please. Thanks, John

P.S. So where can I buy the correct gasket for my 4657 pump.? The bottom round one. Want the real deal.

[William B.]

Re: Leaking 4657 fuel pump

Hi John, I have had that problem before with repo gaskets and regular pump gass. Went to NAPA bought heavy duty gasket sheets and cut my own. I used black paint to darken the color. Judged at NJ regional, judges never noticed the difference and it hasn't leaked in 5 years.

[John D.]

Re: Leaking 4657 fuel pump

Hi John, I have had that problem before with repo gaskets and regular pump gass. Went to NAPA bought heavy duty gasket sheets and cut my own. I used black paint to darken the color. Judged at NJ regional, judges never noticed the difference and it hasn't leaked in 5 years.

Bill, So it is the gasket then. Figures. The original was a corded gasket. Reinforced thick thing. The repro is suspicious.
Maybe I should get some made if we can find the correct material.
I will wait and see if someone else has an idea on who sells the correct gasket. Thanks, JD

[Dave K.]

Re: Leaking 4657 fuel pump

Bill, So it is the gasket then. Figures. The original was a corded gasket. Reinforced thick thing. The repro is suspicious.
Maybe I should get some made if we can find the correct material.
I will wait and see if someone else has an idea on who sells the correct gasket. Thanks, JD

John,

I bought a rebuild kit for my 4657 pump from Corvette World. Included diaphragm and all other gaskets to rebuild. I rebuilt it several years ago and no leaks since. Be sure that the main flange gasket isn't leaking due to loose or stripped screws in the body. These little fine thread screws tend to strip.

Dave K.
Recovering from 7 Springs

[Mike M.]

Re: Leaking 4657 fuel pump

john: when you replace the gasket, apply a liberal coat of spent Levi Garrett juice. also would rather see the pot metal lower lid than the stamped steel critter you're using. mike

[John D.]

Re: Leaking 4657 fuel pump

john: when you replace the gasket, apply a liberal coat of spent Levi Garrett juice. also would rather see the pot metal lower lid than the stamped steel critter you're using. mike

I think my lid or cover is simply a die cast part. I heard it was supposed to be magnesium though but forget. I will have to ask CC about the lid though.
Spent Levi Garett juice may be fine on baseballs but the LWC wouldn't like it. Maybe nice permatex ouzing out would stop the l.eak Then some teflon on all the fittings. Yeah I will try it next week. No respect.
Did u learn about nice boots Doc. Are u sorry for ur sins? Shape up, JD

[John D.]

Re: Leaking 4657 fuel pump

John,

I bought a rebuild kit for my 4657 pump from Corvette World. Included diaphragm and all other gaskets to rebuild. I rebuilt it several years ago and no leaks since. Be sure that the main flange gasket isn't leaking due to loose or stripped screws in the body. These little fine thread screws tend to strip.

Dave K.
Recovering from 7 Springs

David, Wonderful job u did at SS. Thanks for the first class spot for the LWC. Being on carpet was really nice except I did catch a judge sleeping under the car. Had farmers boots on. I am positive the gasket used on my pump (2 or them so far) isn't compatable with gas. I am going to use a nice NOS pump for parts and try one of those thick corded gaskets. If I put spent chew on it the judges will use their mirror and ding me. Should not have to put anything on the gasket. I bought my kid from a Bronx suburb. Probably same kit as yours though.
Seven Springs was a lot of fun and I was sad when it was over. But I am in no hurry for a repeat. JD