Massive fuel pump leak

[38plymouth]

I was just getting ready to take my 38 Plymouth for a drive and was letting it warm up in the garage. I revved the engine a bit and I heard what sounded like a leaf getting sucked through the radiator fan. A few minutes later I back out of the garage and I saw a huge pile gas in the garage and it followed me out into the driveway. I got it all cleaned up and push the car back in the garage and started it quickly and I can see fuel dumping from the fuel pump either around where the pump bolts together with about six bolts or above that. It's dumping so much I'm surprised the car ran. Any thoughts on what might have went wrong? I don't have time to look at it again today and I did take it apart last year to clean out some Gunk sucked up from the fuel tank. It has been working fine ever since. I'm pretty sure I replaced all the rubber lines last year as well as I recall they were cracking pretty bad.

[38plymouth]

Quick edit... I couldn't take it and canceled my plans and went out and pulled the pump. I might have found two things wrong, there is a very short piece of fuel line that goes to the frame and it was loose on the frame side I can't imagine that fuel was spraying up onto the pump to pour off of it but I guess it's possible. I also found where the pump lever is there is a spring inside and each end of the spring looks like it has a little metal cup one of the metal cups was not on the spring and was just floating around inside. I don't see any other sign of where leak would come from. What is the deal with these pumps should I just buy a new replacement or a rebuild kit?

[Merle Coggins]

The line from the pump down to the frame is likely the suction line. Unlikely it was leaking that much gas unless the tank level is higher than the hose. If it was pumping out as much gas as you state, and stopped leaking when the engine was shut off, you have a leak on the pressure side. Inspect everything well. 

[38plymouth]

I tore the pump apart and besides the diaphragm feeling slightly dry everything looks fine. The fuel lines were dry and brittle so I'm replacing them. If it wasn't the lines I'm not sure what it was. It was dumping a lot of fuel.

Any thoughts on where to buy a rebuild kit?

[Merle Coggins]

Then and Now Automotive.

[Dan Hiebert]

Two things come to mind.  First, I had that flexible fuel line from the frame to pump fail on our D24 many years ago.  It was original style, braided hose over a spiral metal conduit style line.  It was only a few years old, and I don't exactly remember what failed, but I vaguely recall the conduit being slightly unraveled, and the hose brittle and deteriorated enough to see that.  Amazingly similar failure description as you gave.  Second, a failed diaphragm alone won't necessarily leak, the pump just won't perform well, unless the edge where it seals the pump's halves together is shot.  If it is even slightly deformed (domed, not flat) when out of the pump, it certainly should be replaced.  Kanter Auto Products also sells a rebuild kit.  I have one on the shelf from NAPA, but its probably about 20 years old now.   

[Dodgeb4ya]

Another "Then and Now"

[38plymouth]

I put the pump back together and didn't see anything wrong with any of the parts or the diaphragm I also put in all new fuel lines since the old ones were very brittle even though they were a year old. I've used nothing but ethanol free gas since then. I'm guessing I got some bad lines from somewhere. Anyhow I thought that was going to solve the problem for today I got the car running and saw that fuel is either dripping from the diaphragm or from the bottom body cover where the two Springs are. In looking at the exploded view of the fuel pump that sure seems like the only possible source of a leak like that would be the diaphragm but I can't see anything wrong with it. I am ordering a rebuild kit today hopefully that solves the issue.

[Sam Buchanan]

If the pump body has developed a crack a rebuild kit won't help........

[38plymouth]

I didn't see a crack anywhere and its leaking less than it was originally. If I get a chance today I will pull it back out and see if I can find the problem.

[Doug&Deb]

I accidentally cracked the inlet port on a fuel pump by over tightening. Took me a long time to find the crack. Good luck.

[38plymouth]

I installed a new fuel pump rebuild kit this morning from then and now and no more leaks. Thank you gentleman for the advice.