Weeping fuel pump fix

[Member 10617]

Does anyone have a suggestion onhow to stop a weeping fuel pump. Is there any use to tightening the small screws on top of the pump? If so, any cautionary advice?

 

[DNK]

Where's JP when we need him.
To many possibilities.

Lex, you have to be careful how you phrase a question around this bunch. They are brutal,specially during the dread of Winter.

 

[trrdster2000]

Ed, you didn't say where it's doing the weeping. Around the glass bowl, in and out fuel lines or oil running down the block?????

A new cork gasket in the fuel bowl should help. Buy some cork material and make one, if it's a quick fix you need.

Wayne

 

[Member 10617]

Odd thing. The weeping is occurring on top of the pump housing itself. I thought the fuel might be coming through the small screws that hold the top of the fuel pump on. But I'm really don't know. Here is a photo. I sopped up some of the fuel so it doesn't show as much as it was showing earlier.

 

[DNK]

Wayne suggested the top gasket, don't know about that pump but it could be that or even up line from it and running down the hose?

 

[MGTF1250Dave]

Aloha Ed,

A possibility is the compression fitting for the fuel discharge pipe. Be careful not to over tighten the nut, the threads on the pump will usually give before those on the nut. The fuel pump diaphragm is a possibility, but if that was leaking I don't think you would see fuel on top of the pump. IMO, the more common source of leaks on these pumps is around the glass bowl, either due to a bad gasket (neoprene or cork has perished) or the metal mating surface is distorted. In attempts to get a better seal, the clamping nut is over tightened and the wire bail pulls down the sides of the cast cover. Slight leakage from around the glass bowel might be blown back on to the cover.

 

[Member 10617]

Dave,

I don't think it is leakage being blown back because the weepage takes place even when the car is sitting for a number of days. As I look at the pump and the photo more closely, it appears that fuel could be coming out around the nut shown at 11 o'clock on the photo (is this the compression fitting for the fuel dischage pipe?). That could explain why fuel is pooling in the little trough that circles the top of the fuel pump. If so, should I try to tighten it slightly and see if that helps, or am I risking over tightening it, as you caution.

 

[DrEntropy]

Is there a square-cut O-ring at the fitting of the fuel line? That's my WAG.

 

[Member 10617]

I don't see any kind of o-ring at the fitting of the fuel line. Just the threads going into the top of the fuel pump.

What would happen if I eased the nut out a few threads, brushed on a little non-hardening gasket sealer, and retightened the nut? If the leak is coming from there, that should stop it, and I wouldn't have to possibly over-tighten the nut. I've had this work with other fuel and oil leaks. I would be careful to make sure none of the gasket sealer actually got into the pump or the fuel line.

 

[TR3driver]

You could try the gasket sealer, I guess, but I don't hold a lot of hope that it will work for long. Also tighten firmly, but don't go overboard (guess who cracked a housing that way).

The real issue is that that joint originally used a special brass compression sleeve that is no longer available. There have been several solutions suggested, mine was to cut a new nut with an extended tip so it could bear down on the compression sleeve without hitting the bottom of the threads. This solution is probably more practical:
https://docs.google.com/viewer?a=v&p...5YTUz&hl=en

Also, if it is leaking around the screws for the top cover, then most likely IMO the diaphragm is being attacked by the fuel and needs to be replaced with a new "ethanol resistant" diaphragm. But the fitting is much more likely to be the problem spot.

 

[sail]

I had a pump with a similar problem. It was a repro with no primer and did not have caps on the operating pin which can be a problem as discussed in this forum. Worse it would sweat fuel all over although I could find no leaks. Chia Pump is now in the trash.

 

[Mychael]

The alloy bodies on those pump get a bit tired with age. It's very easy to strip the threads by overtightening the screws that hold the top on, having said that they do tend to work loose. Worse case scenario is to drill right through and use a small bolt and nut instead of a screw. I've done that in the past.

The other thing that happens with age/vibration is the nut which holds your fuel feed line gets loose and tighening it up tends to flare out the pump body so you never get a good seal.

If it's fuel your leaking then either the joint between top half and body or the fuel feed line are th emost common places you'll get leaks.

Because of the 'head' of fuel you have from the tank you can always get some leaking even if the motors not running.

 

[Member 10617]

Many thanks. I'll proceed cautiously. I'll put a little gasket sealer (the kind I use is non-hardening and not affected by gasoline) on a few of the threads and tighten the bolt with care. I'll also check the screws holding the top on.

Just to make sure I have the right nut and fuel line in mind, I am referring to the fuel line on the right coming out of the top of the fuel pump pictured in my posting. I assume this is the fuel discharge pipe (Sorry, I'm just learning this auto language). The other pipe or line and nut, to the left, are fine: no leaks.

First thing I'll do after Christmas. Merry Christmas to all! (Perhaps Santa will bring me a new fuel pump.)

 

[hondo402000]

how about wraping teflon pipe tape around the threads and some on the end of the pipe just before the flare, thats worked for me on a propane tank

Hondo

 

[TR3driver]

Just for clarity, the threads do not seal in that joint, so adding "teflon" tape or sealant to them is pointless. The seal is supposed to be between the compression sleeve (or gland if you prefer), the pipe and the pump body. So if you are going to try adding sealer or tape, it only makes sense to do it around the sleeve rather than on the threads.

The pump also holds pressure (or should) after the engine is stopped, so it can go on leaking until that pressure is bled off. Fortunately that is only an ounce or two, but it looks like a lot.

And yes, the outlet fitting is more to the right and top in your photo. The fitting to the left and bottom is the inlet fitting, which is much less troublesome.

 

[bigjones]

FWIW, my pump leaked until I removed the filter in the pump. Now it is bone dry. I did install an in-line filter between pump and carbs.

 

[TR3driver]

FWIW, my pump leaked until I removed the filter in the pump.

What filter? Do you mean the brass screen above the sediment bowl?

 

[trrdster2000]

Ed, take both lines off and use some Teflon tape around each fitting. Get it at Lowes or any plumping supply house. A couple of warps in the opposite direction of the treads, (counterclockwise).

Wayne

 

[bigjones]

What filter? Do you mean the brass screen above the sediment bowl?

Yes, that's the one. This was about ten years ago so details aren't too clear but I believe I done some sort of rebuild on the pump - nothing too involved - definitely no crimping of parts.

I guess I should have kept a log book or something. It was a TRF part so I can't blame the dimensions of the filter - not sure what the problem was but it stopped leaking when I removed it and just opted for an in-line filter.

Cheers!

 

[Geo Hahn]

I too doubt that teflon tape will solve the weep you're getting around that outlet compression fitting.

You might try taking hold of that hard line and wiggling it a bit as you tighten the nut a flat or so. Sometimes it doesn;t quite want to seat as you tighten the nut and the wiggle (even if you can't feel movement) will help. Or maybe I'm just superstious.

It can be nervous work tightening that dingus but that may be the only way to stop that leak.