looking for a leak on a gas tank 93 yj

Bchomegrown · 03-02-2009, 01:16 PM

Last week when I was in the BK drive thru (after filling up) some lady came up an told me I was droppin gas. I got out checked an seen It was just a drip, but rather almost free flowing outta the tank. Id say there was at least a litre on the ground. It stopped almost immidiatly after I took the cap off an released the pressure from the tank. So I dropped the gas tank looking for a leak, armed with some gas tank epoxy I was determined to get it done. I took the shield off with it still hooked up, I let it run for about 15 mins still couldnt find a leak. Now I'm not sure where it could be, I'm the second owner of the jeep the Previous owner was a lady an she had it in the dealer for every scheduled maintenance so I'm assuming the recall for gasket was done on it. I'd hate to put it all back together with out finding the leak.. any suggestions would be appreciated

jbach · 03-02-2009, 03:04 PM

do you have the tank dropped? tip it on it's side away from the filler. unless it was leaking at the filler neck. it's there somewhere.

93jeepyj · 03-02-2009, 04:10 PM

may of been a loose hose clamp ive had mine piss gas out like that before too.

Gonewhln · 03-02-2009, 04:27 PM

I had this issue also i replaced the gasket around the fuel pump it was 5 bucks then i also replaced the return and sending tubes i want to say they were 3/8 inch tubes (rubber) i didn't quite tighten the hose clamp on one of them and it dripped a little until i could get the tank dropped down again.

Bchomegrown · 03-02-2009, 04:32 PM

ok, well I tipped the tank all around unless theres a leak in one of the seals theres no hole in the tank. The other thing i noticed was that there were no clamps for 2 of the connections. The 2 brass knuckels in the middle of the tank (i think its the fuel sending unit) had clamps on it, however the two outer plastic ones did not. also the line that connects the two plastic elbows together (it has a t connection) is pinched, is this a problem ?

Gonewhln · 03-02-2009, 04:39 PM

could be i pinched hose may cause pressure build up and creat a leak some where.

try replacing the old hoses they maybe dry rotten.

**Mobile_Homie** · 03-02-2009, 04:40 PM

The two outer lines are for the 'roll over valve', they shouldn't leak. Prolly the filler tube leaking.

Bchomegrown · 03-02-2009, 04:41 PM

ok thx, off to the part store

**jbolty** · 03-02-2009, 04:56 PM

the rollover valve or the hoses and fittings can leak gas if the the tank is full, or it's tilted to the right.

tazme695 · 03-02-2009, 05:07 PM

Notes

NOTE: In vehicle rollover valve is in the inverted position the plunger is forced against the guide plate and raw fuel is prevented from flowing through the valve orifice into the fuel tank vent tube.

NOTE: These vehicles are equipped with only one rollover/pressure relief valve. These dual function valves relieve fuel tank pressure and prevent fuel flow through the fuel tank vent lines should the vehicle be rolled over. To test the Purge Shutoff Switch perform the following procedure.

1. Inspect fuel and vapor hoses for proper routing, cracks, or restrictions.
2. Inspect fuel tank cap for proper seal and fit.
3. Remove fuel tank vent hose from EVAP Canister. Apply light air pressure (3-6 psi.) to the Fuel tank filler tube. Air flow should be present at fuel tank vent hose. If air flow is not present, and Fuel Tank is not over-full, replace Pressure/Relief Rollover Valve.

4.7stroker · 03-02-2009, 06:49 PM

I think you should put the tank back in fill it up and find the leak with a Zippo.

WARNING this procedure could be a health hazard.

Dwayne

azgurney · 03-02-2009, 08:46 PM

My old tank would leak when it was over 1/2 full. There is seam on the platic tank on the back side of the tank 1/2 way up that was cracking. I tried patching it with various tank sealers and then jb weld but nothing would hold up very long. I ended up replacing the tank.

Obcean2 · 03-02-2009, 10:19 PM

When I had my fuel leak on my 93 it ended up being a dry rotted fuel line, and the leak was about a foot or so in front of the tank. When the system was under pressure gas would leak and run back the line to the top of the tank where it would then drop to the ground. I thought I would never find the leak. Good luck with yours!

nickdestfino · 03-02-2009, 11:00 PM

My 89 had the fill hoses dry up and crack and would leak anythign over half a tank. Fuel would splash around inside and spill out the hose. I had a guy come running up to me on a trail and tell me I ruptured my talk. I hoped out looked at it grabbed a beer and kept on down the trail.

Bchomegrown · 03-03-2009, 11:02 AM

Well the guy at the parts store (my buddy) told me to just go tighten all the hoses before I buy new stuff. So yesturday I was able to put the tank all back together making sure to over tighten all the hose clamps. I could only find one zap strap so I put that on one of the rollover valves. I sloshed the tank all over, nothing. I took a lil bit of gas an poured it on the rubber seals of the rollover valves, nothing. So Im left thinking its a hose, but not one of the main ones, I think if it was it would at least have dripped while I let it run for 15 mins. I also bent the one hose (connecting the 2 rollover valves w/ the T connection) back in to shape. While the tank was out I figured I'd give my self 5 extra gallons, may or may not turn out to be a good idea. When I took it for a test drive last night I also noticd the fuel gauge goes lower than before. Between the zap strap an bending that hose back into shape I hope one of them work. Thanks for all your input everybody given me lots of good tips