hubturn

I've had it with the slight hint of gas fumes in the trunk and cabin when I don't drive the '95 Cabriolet every day. Every fitting I can get to is dry. I believe there is a crack somewhere in the fuel expansion tank or the lines running to the EVAP canister. Anybody have a picture of what the bottom of the fuel tank looks like when removed and any helpful hints or gotcha's in removing the fuel tank? Thanks.

Rusty Spokes

Hubturn..have you checks the fuel lines around the fuel pump? I had a line.. a short one..that went to a crimped connection that was weeping fuel.

hubturn

I have checked every connection and line that I can see and feel. That's why I'm focusing on the fuel tank expansion chamber and the EVAP system. There's a Audi Self-Study program concerning the EVAP system, which was highly informative. Essentially the system dumps the fuel vapor into the EVAP canister which is in the right front wheel well in close proximity to the air intake for the heater box, then sucks it back out and into the throttle body via the canister purge regulator valve and that wacky hose that has more bends in it than a politicians version of the truth. Naturally, Audi has a special testing device to check for EVAP leaks. In direction violation of instructions in the Self-Study guide, I plan on putting a slight pressure in the fuel tank and listen for an air leak. Audi warns that if you do that, the sky will fall, the sun will not rise, and that you will damage every component in the system just before your garage explodes from fuel vapor. We will see. Mostly, I'm worried that if I pull the fuel tank to get to the expansion chamber, I'm going to screw up the connections than come out of the bottom of the fuel tank and through the body. That's why I want to know if there are any tricks to removing the fuel tank.

Rusty Spokes

Never had the fuel tank out of my car and you have a good question..I don't know any tricks..sorry ..over on the German website there was fellow that had raw fuel leaking up into his charcoal canister which turned out to be a defective Petrol Tank Expansion Chamber 8G0201891A..this may be relevant for you.

Do you have some pressure in the fuel tank when you go to add gas at the gas station? Mine has some..not much..when I re-fuel. The pressure would indicate that the evaporation system is working.

See the link here..and use Chrome to translate:https://www.audi-cabrio-club.info/fo...raftstoffdampf

The fellow got the tank out without much drama.

Here is a YouTube of his fuel pouring out of the evaporation line up front:

hubturn

Thanks for the help. I put some pressure in the tank and couldn't hear any escaping hiss. Have the back seat out, slid the tank back an inch, took out the ski pass through to look and couldn't find anything wrong on visual inspection. The expansion tank is tightly wedged in between frame members. I had hoped to slide it down to look at it. No way. The fuel tank has to come out to get to all this, and it's pretty obvious that this is a job second only to the heater core job for being a royal pain. I think I'm going to live with it.