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Fuel leak in trunk

2.9K views 10 replies 5 participants last post by  Tifosi  
#1 ·
Hello. I noticed a pretty strong gas smell coming from the trunk so I pulled the carpet and noticed that there was a nice pool of gas sitting on top of the sending unit (gasp). Turns out that the file line coming out of the sending unit had a nice crack in it and when moved in a certain way would let gas spill out. No problem I though - even a newbie like me can replace a hose. So.. I replaced the hose and fired her up. All was wonderful so I ran her around the neighborhood for 20 minutes or so only to discover that I now have a leak from what looks like the actual sending units screws. (fuel pools up there and bubbles from one of the screws. There seems to be an abnormal amount of pressue also as when I unscrew the gas cap air whistles out pretty good.

Can it have anything to do with the vapor system in the trunk letting too much pressure build up? Honestly, I dont really know what all that vapor stuff in the trunk does.

Perhaps unrelated, but the gas guage has been even more inaccurate than normal *grin*.

Any ideas what I should do? My simple repair has turned ugly :( I would like to do this one without running to the mechanic with my tail between my legs.

Thanks!
 
#2 ·
J,
I replaced the push pump which is attached to the sender and when I finished I also had a raw fuel in car smell. I looked over my work but it all looked OK. So I ordered a new sender gasket from International Auto Parts and installed it. Problem solved. For some reason, when I reused the original gasket the first time it did not properly seal, even with the screws tightened down correctly. The new gasket is very reasonably priced. Give this a try.
Robert
 
#3 ·
It also doesn't hurt to check that the vapor line running from the vapor recovery tank up to the engine is clear. Mine drooped and melted where it goes over the tail pipe, basically cauterizing it.
 
#4 ·
Thanks guys - I'll check those out. $2.95 at IAP is a pretty cheap repair so i hope thats the ticket. Of course i get to get gas everywhere again replacing it.

Farace - gas is actually pooling at the sender - not just a vapor leak. Could a broken vapor line cause that?

How can you tell if your check valve, and the little valve that has a small (1 cm) external filter are working? And does the little valve let air in or let air out?

Thanks again.
 
#5 ·
How can you tell if your check valve, and the little valve that has a small (1 cm) external filter are working? And does the little valve let air in or let air out?
Remove the section of hose they are on.

Shake the one way valve and listen for rattle (it's a ball bearing on a light spring)

If you get rattle, blow through each end and it should only allow air to pass in one direction (the direction the arrow is pointinf toward)

The little pancake diaphram looking one should only pass air from the outside in if you blow through it.


The metal check valve can be cleaned with carb cleaner and some good shaking and the plastic diaphram can be gently pried apart at the center seam and cleaned with soft cloth and alcohol.
 
#6 ·
Thanks. I could not blow through the check valve in either direction, but after smacking it around a bit I can now blow through in the correct direction. It whisles like a kazoo and is fairly hard to blow through though. I will try some carb cleaner after I purchase some. If that doesn't help is there a place I can get one? The plastic diaphram can now be blown through as well after I did some minor cleaning from the outside and forcably blew air through it. Its also somewhat difficult to blow through. Could this have anything to do with my fuel leak or is it unrelated but good to have fixed anyways?

I ordered the gasket and it should be here tomorrow. I dont want to drive a car with a gas leak in the trunk - I can't belive that's safe :)
 
#7 · (Edited)
Thanks. I could not blow through the check valve in either direction, but after smacking it around a bit I can now blow through in the correct direction. It whistles like a kazoo and is fairly hard to blow through though. I will try some carb cleaner after I purchase some. If that doesn't help is there a place I can get one?
The carb cleaner should bring it pretty good for you actually, once it's thoroughly dry inside.

The plastic diaphram can now be blown through as well after I did some minor cleaning from the outside and forcably blew air through it. Its also somewhat difficult to blow through.
Yeah, that's kinda common. As long as you actually can blow through it it'll be OK.

Could this have anything to do with my fuel leak or is it unrelated but good to have fixed anyways?
The metal one way valve sticking shut can help force vapor out wherever it can find a path, so yes, it 'might' have had somehting to do with your issues.

And yes, it's good to have it fixed anyway as it ensures you don't get the trunk stinkies, (well, if every other part of the *system is working optimally*), the vapor gets recovered and reburned and the tank will neither vacuum lock or pressurize itself.

I dont want to drive a car with a gas leak in the trunk - I can't belive that's safe :)
As long as your cigarette isn't lit when you pop the lid you should be ok :D



*There's a link in the FAQ at the top of this section that can really help the trunk odor problems, even when things are working right.
 
#8 ·
I replaced the hose...
What sort of hose clamps did you use? The standard hardware store worm drive clamps may not seal adequately. They can allow the hose to bunch up instead of squeezing it 360 degrees. A proper FI type clamp should be used.

Did you see this thread: Fuel leak at sender?


I now have a leak from what looks like the actual sending units screws. (fuel pools up there and bubbles from one of the screws. There seems to be an abnormal amount of pressue also as when I unscrew the gas cap air whistles out pretty good.
The tank should not be under any pressure. More likely a slight negative pressure (for emissions purposes). Fixing that check valve and air inlet valve should help.
 
#10 ·
Thanks all. I replaced all the vapor line hoses except the long one that goes from the trunk to the engine bay (seems good), cleared out the different valves, and replaced the gasket. The leak apreas to be gone and I don't seem to have any pressure anymore! The real test will be when I run it for a week or so I suppose.

However, now my gas gauge is very "active". Seems even more bouncy than normal. Any thoughts? I go from full to 3/4 and back every few seconds.
 
#11 ·
If you pulled the sender, likely you put it back in wrong. The float arm should be pointing out to the right/center of the trunk.

If it's fore or aft, the float will move with every bump, stop, go, upshift, downshift, brake application, whatever and the gauge will indicate it.

If the arm is in the correct position and the gauge does it even when not moving for a period of time, (long enough for fuel to stop sloshing), you prolly have a loose or dirty connection at the sender.