gasoline weeping from around pump face-plate pipe-perimeter: '87XJ

'87 XJ 4.0L:
Few weeks ago started to smell little gasoline vapor from rear after each tank fill-up... with tank full got underneath it yesterday and found there is a significant weeping-leak from around the base perimeter of what looks like the return metal pipe into the round face-plate (right next to the double-wire connector for the pump).

It's not the fuel pump that's leaking (pump is internal, it was replaced ~ 15 months ago) ... it's the base of the smaller-diameter outside metal pipe into the round face plate.

Since this is a 13.5 gallon tank I don't have the replacement option of buying and installing the AirTex complete assembly (which is for the larger tank size).

So:
I'm thinking about trying to seal the weep around the metal pipe base with layering a ring of Permatex Form-A-Gasket#1 followed and then after it dries additioning a ring of 1 of the following on top of the Form-A-Gasket:
- JB WaterWeld, or,
- Permatex Instant Gas Tank Repair, or,
- Permatex Gas Tank and Radiator Repair.

Has anyone done a similar repair ? ... if so, what worked for you ?

Thanks.

If I understand correctly, you're talking about the pressure and return lines that run through the access cover on the tank. If you're sure it's coming from the return line where it goes through the cover, it's either a failed braze joint, or a cracked tube. As long as it's not under pressure, any of the epoxy gas tank repair kits will seal the leak. Just be sure to get the surface clean before applying the epoxy.

If the problem is a failed braze, this will be a permanent repair, if it's a cracked tube, it'll be temporary, until the crack works all the way around the tube.

Don't use form-a-gasket. Most types are fuel-proof.

Thanks for that answer.

The slight weeping is from somewhere around the base perimeter of the metal pipe for the smaller-diameter fuel-hose fitting that is located lower on that cover...
... I confirmed this with the tank full and the hose off the weeping occurs and I can cause the flow to increase a bit more via SLIGHTLY wiggling that metal pipe.

This is most likely an OE cover from ~ 1987... the base diameter of that metal pipe widens about an eighth of an inch before it goes thru the cover...
... but there does NOT appear to be a braze around the pipe's base diameter looking at it from the outside
... it looks like that metal pipe smoothly goes thru the cover.

So far, I have observed the weeping only when the tank is full... I have not been under there looking at this with (let's say) a quarter-full tank.

Regardless,
I have both the Permatex Instant Gas Tank repair (#12020) and the Permatex Gas Tank & Radiator Repair (#80884) coming toward me...
... since this is a small diameter I want to get a feel for working with both epoxies before
applying around the base... there is not all that much room to work around that pipe base with leaving the electrical connector on...
... I am intending to apply the Permatex expoxy fix with no more than a quarter-tank full (I'm expecting that weeping will not occur with a quarter-tank full).

I have some JB WaterWeld but that stuff sets-up too fast for me (to use as the base layer around this pipe) ... after the Permatex expoxy fully cures I may decide to add a layer of WaterWeld on top of the Permatex not so much for additional leak-protection but more for further stabilizing that pipe to the cover.

I had this very same thing on my '93 XJ. I pulled the pump, and let it air out for a day
to allow time to diffuse any fuel vapors. Then I soldered around the tube with a propane
torch (both sides of the metal disk). Getting the pump back in and properly seated was a
chore, but I've had no leaks since.

Dragonslayer said:

I had this very same thing on my '93 XJ. I pulled the pump, and let it air out for a day
to allow time to diffuse any fuel vapors. Then I soldered around the tube with a propane
torch (both sides of the metal disk). Getting the pump back in and properly seated was a
chore, but I've had no leaks since.

Click to expand...

Your fix would seem to be the best route.

Agreed, soldering would be the "best fix, but short of dis-assembly, the gas tank repair epoxies are pretty good. I've used various epoxies on 3 different gas tanks(filler vent, tank vent, and one puncture) and had good luck all three times.

About three weeks ago, my '87 started smelling really strong at the back of the rig every time I topped off. This week, I see the top of the tank is moist with gasoline following topping off.

Guess I am going to be dropping the tank and checking on the pump mounting plate!

Thanks for the great description and recommended solutions!

Rob

If the leak is around the perimeter of the in-out pipes thru the sender cover (as was on my '87XJ), and if you go with the less-labor method of applying epoxy with a 1/4 tank full, then my direct experience feedback is to let the epoxy fully set for at least 24 hours before driving and/or filling-up the tank.

I went that route of applying epoxy (a lot of the Permatex Instant Gas Tank repair epoxy) to the pipes outside perimeters on that cover and the gasoline weeping was significantly cut-down but not to zero (but really close to zero, basically at most a slight dampness with a full tank).

But more so: when I look from underneath up-around the side of the tank body towards to the tank top there appears to be a serious amount of rust along the top edges of the tank body - and I image there is a lot more rust on the level-surface of the top of that OE 13 gallon capacity tank, and,
on the bottom-side of the cargo area floor-pan.

So:
my current plan next Spring is to drop the tank and replace it with a new 20-gallon Dorman tank and the AirTex E7091S pump/sender/cover assembly along with derusting/patching the floor-pan of the cargo area

Yes, the tank and pump/sender parts are over $200 via RockAuto but since I've changed a bunch of other stuff this past Summer (engine/motor mounts, P/S pump and lines, new cat+catback, successfully patched an exhaust manifold pipe#6 crack with POR-15 FireSeal2000) and am now near the project-end of derust + sheetmetal + epoxy the passenger-side floor-pan holes it looks to me that I am doing somewhat of a restoration project on this daily-driver.

If it wasn't that I like this '87 XJ so much (and the engine and auto-trans are in fine shape for ~ 322K miles) I wouldn't be doing all this.

Yea... if it's broke then fix it... otherwise, I need some rest.

1 more thing... a suggestion: instead of using a heat-generating incandescent bulb with a 110V trouble-light to look up into the gas tank body area the first time (at least until you find what you're dealing with for a leak),
it is likely safer to use a flashlight... I used a miniture LED flashlight for all the epoxying that I did onto that tank's front sender cover... bought the flashlight in AutoZone near the cash-register counter for something like $2.50 (the 3 AAA batteries were included).
Causing a fire/explosion while trying to make the Jeep more better would be a negative outcome.

MikeESoc2 said:

'87 XJ 4.0L:
Few weeks ago started to smell little gasoline vapor from rear after each tank fill-up...
Since this is a 13.5 gallon tank . . .

Click to expand...

While you're at it and if you decide to pull the pump assembly again, remember there is no such thing as "a 13.5 gallon tank". They are all the same size, the "little" tank just has a vent tube that goes further down in the tank.

Seal the leaks, replace the "O" ring and consider this (http://go.jeep-xj.info/HowtoFuelTank.htm) mod. or just check out the photos to see where the stock 20 gal. vent ends.

Bet you anything you have a leaky fuel pump flange seal/o-ring. Fuel will leak down the flange and looks like it is leaking from the pipes. I chased this same goblin and it turned out to be the seal.