Facelift Fuel Tank Replacement

I did recently replace that ring. (OEM used) as well as gaiter (aftermarket, although apparently thicker than OEM?)

I seriously think the tank collapsed somewhat, which explains the mysterious fuel level sender issue I have. I believe the top of the tank has depressed in and the fuel could be seeping through the top seal?

I’ll have time on Sunday to investigate. I’m going to check the top of the tank to see if there’s any sign of deformation. Should be pretty easy.

If all looks good, I’ll get going on the filler tube.

If it looks deformed, I’m going to try to push in some compressed air. I read somewhere else that 10psi should be more than enough to fix it.

Be careful that compressed air though doesn’t damage some other component of the fuel system, VK … :grimacing:

I have spare evap flange and fuel sender. I guess I should have another o-ring and gaiter on hand.

Not sure what else can go.

If the pump goes…at this point it goes.

The question is…how much fuel should I have in my tank? half? empty?
I

btw, what all was involved in r/ring that sealing ring, VK? If not a lot of work, I might attempt it myself in the near future to see if that gets rid of my passing fuel smell issue w. Superblue. :thinking:

Small hands.

Probable destruction of the existing gaiter.

You basically have to remove the hose clamps holding the gaiter in place. Then unscrew the filler neck from the top. Then pull. Pull like you’ve never pulled before. That old o-ring has bonded to the metal so it’s not gonna let go very easily.

That’s it.

Make sure to reinstall the bottom half of the new gaiter before putting the filler neck back on. Petroleum jelly can be used to lube everything back up when reassembling.

Mat under tank will smell forever.

ozone machine eliminates the odor from the mat.

Pumped in some air…sure enough the thing popped! It had collapsed for sure.

Update: filled up tank….smell is back.

How can I pressurize the tank and let it sit, to see if there’s a leak? I couldn’t figure out how to put a pressure gauge on the tank. I plugged the filler with a 2” pipe plug, then pressurize the tank using the rubber hose on the evap flange. I think it’s a 5/16” hose.

The gaiter did not expand when I pressurized the tank, so I thought the o-ring was holding.

Take it out and test it on the bench.

I think you’ve 2 options left. Either do the above or work through cause and effect methodically (you say sometimes it smells and some times it doesn’t). That may narrow it down a bit. FWIW.

Frankie

So far I don’t get an odor when I fill the tank short six gallons…when the tank was collapsed. When I topped it off, I got an extra 2 gallons of fuel, so technically I was about 8 gallons short.

I guess the next option is to add one gallon each time and see at what point the smell comes back.

Put a “T” fitting in the 5/16 hose. Add pressure gauge to one end and schrader valve to other end. Pressurize. Cap valve. Wait 24 hours. You should have an answer.

Will that necessarily tell you that its the tank and not a connection or seal?

Frankie

At post 34 and 36 you half filled and then topped up the tank and got no smell - you thought you had fixed it. Then at post 37 the smell returned. What happened with the car between 36 and 37 that may have caused the smell to return? You are looking for a pattern.

Frankie

Bernard, I didn’t have any of that Gates Barricade 5/16" hose left, and all of my tees have sharp metal barbs on it. I don’t think I would have been able to get it off. I also didn’t have a schrader valve that worked, but I ordered a fitting and assuming it gets here by Friday, I’ll go back in this weekend.

Frankie, I parked the car in the sun and the smell came back after a full tank fill up. When I was six gallons short, the smell never returned. I think I was too quick on the draw when I posted success on Post 37.

I think pressurizing the tank and leaving it be will limit the leak points to (a) the tank (b) the gaiter connection at the filler neck and (c) the vent at the filler neck. It would eliminate the piping out to the charcoal canister since I’m unplugging it at the evap flange to pressurize with compressed air.

If I can get confirmation on the tank leak, I can (a) add smoke and see if it comes out anywhere I can see it, (b) I can then disconnect the filler neck and block that off using a smaller pipe plug (c) block off the hose going to the vent at the filler neck.

I have to say the fuel smell is very much stronger than it had been in the past. I may have worsened whatever it is causing the leak by pressurizing the tank.

Any suggestions on a smoke product to use for this? I’m assuming blowing in cigar smoke might be hazardous to my health…and having a lit cigar anywhere near the leaking tank might make for an explosive experience.

Will that necessarily tell you that its the tank and not a connection or seal?

Frankie

I think you would have to test the seals/connections using the old soap bubbles method.

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Soap bubbles…of course. I hadn’t thought of that! Thank you.

I’ll spray the mixture on the joints (that I can see) and see what happens!

You say the tank was “imploded” and that pressurising to 10psi caused it to “ping” out. Then you say you left it in the sun with a full tank and the smell returned. The tank should neither pressurise nor “implode”. Are you sure the evap/vent system is clear? Leave it in the sun again for a few hours then open the filler cap. Is there a whoosh as pressurised fuel vapour is released?

Frankie

I had the Rochester Valve installed backwards a year ago. That was likely what created the collapse. It affected the fuel gauge’s ability to show a full tank. I’ll be replacing the sender with a (pricey) OEM one that I had bought, suspecting the aftermarket wasn’t right. I bent that aftermarket arm slightly to show me the F, but I think I can go back to an unbent sender arm now. But that’s a different story. There’s no whooshing sound from my tank, haven’t had that at least since I turned my Rochester valve back around.

The smell immediately returned after I topped off the tank yesterday. I’ll have to drive it around, burn off about 8 gallons. I’ll ozone the trunk out, which should eliminate the odor, and then see what happens. If all is clear, I’ll soap up the joints, which will include the visible tank seam and (1) the evap flange (2) fuel sender flange (3) fuel filler vent and (4) the gaiter, both top and bottom, then pressure her back up a little and see if she holds. If not, hopefully I’ll see some bubbles.

Game over.

When I went to my car this afternoon to drive home, there was a puddle of gas under the drivers side rear wheel.

I came home and got the rear up on ramps. The bottom mat was pretty saturated. The hole for the metal tube that heads over to the charcoal canister had a steady drip of fuel coming through it.

I removed the hose at the connector and it wasn’t coming from inside the tubing. The gas was using the outside of it to make its way out of the trunk shelf.

Theres now a major leak. I don’t have a garage or the means to sump and store 18 gallons of fuel. I’m taking it to a shop. They’ll likely recommend reconditioning the tank I have, after all any other tank I find will be 25+ years old like mine, without any guarantee that it will not cause me any problems in the future.

Clearly the compressed air I sent in got me where I am today. Not sure if I created a new problem or simply exacerbated the previously existing problem…

Oh no, VK … and on a '96 MY, no less … :disappointed: