Odyssey Gas Tank Leaks only when 100% Full

If anyone can help here appreciated. I have a 1999 Odyssey

I had an accident 3 weeks ago where my car rolled down my driveway (with no
one in it) and ran over some landscaping rocks. The rocks crushed my gas
tank.

They replaced the gas tank (and a few other minor things) - but now when I
fill up the tank completely - there is a smell of fuel in the car and there
is a small amount of fuel dripping from somewhere out of the top of the tank
and dripping on the garage floor. I can't see where its coming from but
obviously from the top of the tank somewhere. Again - this problem only
occurs when the tank is 100% full. If 95 % full - no leak. The small
amount of gas that leaks stops after the car has been turned off for 20
minutes (it does not continue to leak all night or anything like that).

Obviously - the van goes right back Monday morning - but I just wanted to
know - if not the tank - what else at the top of the tank holds fuel and
could be leaking for a short time after the Odyssey is turned off.

All help appreciated

 

I might also add - it seems to me that to to see what part is leaking - you
would have to take the tank down. But with the tank off (and emptied) - it
may be difficult to see where the leak was coming from if nothing is
obvious.

 

I might also add - it seems to me that to to see what part is leaking - you
would have to take the tank down. But with the tank off (and emptied) - it
may be difficult to see where the leak was coming from if nothing is
obvious.

 

I might also add - it seems to me that to to see what part is leaking - you
would have to take the tank down. But with the tank off (and emptied) - it
may be difficult to see where the leak was coming from if nothing is
obvious.

 

A leak like this is often the overflow tube that runs alongside the filler
neck. A clamp might be loose or missing, or the tube may be cracked where
it comes out of the tank.

To investigate thoroughly, you'd need to have the car up on a hoist, and
have a strong light. If this is a collision repaired car, ANYthing could be
damaged. Anything from broken tank seam to a split hose to a broken pipe to
missing clamps.

 

A leak like this is often the overflow tube that runs alongside the filler
neck. A clamp might be loose or missing, or the tube may be cracked where
it comes out of the tank.

To investigate thoroughly, you'd need to have the car up on a hoist, and
have a strong light. If this is a collision repaired car, ANYthing could be
damaged. Anything from broken tank seam to a split hose to a broken pipe to
missing clamps.

 

A leak like this is often the overflow tube that runs alongside the filler
neck. A clamp might be loose or missing, or the tube may be cracked where
it comes out of the tank.

To investigate thoroughly, you'd need to have the car up on a hoist, and
have a strong light. If this is a collision repaired car, ANYthing could be
damaged. Anything from broken tank seam to a split hose to a broken pipe to
missing clamps.

 

There is an access panel to the fuel pump under the carpet and second row
seats. Perhaps you can see something from there. There are a ton of pipes
and hoses in the top of the tank and it will have to be lowered to get to
most of them. They should be able to find the leak with the tank empty with
a smoke test or pressure test.

 

There is an access panel to the fuel pump under the carpet and second row
seats. Perhaps you can see something from there. There are a ton of pipes
and hoses in the top of the tank and it will have to be lowered to get to
most of them. They should be able to find the leak with the tank empty with
a smoke test or pressure test.

 

There is an access panel to the fuel pump under the carpet and second row
seats. Perhaps you can see something from there. There are a ton of pipes
and hoses in the top of the tank and it will have to be lowered to get to
most of them. They should be able to find the leak with the tank empty with
a smoke test or pressure test.

 

likely the filler pipe to tank hookup

 

likely the filler pipe to tank hookup

 

likely the filler pipe to tank hookup

 

As the others say - the attachment of the tank to the filler neck is the
obvious trouble point.

Troubleshooting is pretty much the same as testing. The cap is replaced with
a pressure adapter and the tank is pressurized to a pound or two - if it
doesn't hold, it's a matter of listening/feeling for the leak. I've done it
before in our old Volvo with an adapter to a bicycle pump, and it's amazing
how much hiss there is from a very small pressure.

Mike

 

As the others say - the attachment of the tank to the filler neck is the
obvious trouble point.

Troubleshooting is pretty much the same as testing. The cap is replaced with
a pressure adapter and the tank is pressurized to a pound or two - if it
doesn't hold, it's a matter of listening/feeling for the leak. I've done it
before in our old Volvo with an adapter to a bicycle pump, and it's amazing
how much hiss there is from a very small pressure.

Mike

 

As the others say - the attachment of the tank to the filler neck is the
obvious trouble point.

Troubleshooting is pretty much the same as testing. The cap is replaced with
a pressure adapter and the tank is pressurized to a pound or two - if it
doesn't hold, it's a matter of listening/feeling for the leak. I've done it
before in our old Volvo with an adapter to a bicycle pump, and it's amazing
how much hiss there is from a very small pressure.

Mike

 

I would suggest to keep the van out of the garage until it is fixed. It is
not worth a chance for a fire hazard like that in your home. I hope the
garage is not attached to the house. Be careful anything can ignite and
cause fire or explosion.

 

I would suggest to keep the van out of the garage until it is fixed. It is
not worth a chance for a fire hazard like that in your home. I hope the
garage is not attached to the house. Be careful anything can ignite and
cause fire or explosion.

 

I would suggest to keep the van out of the garage until it is fixed. It is
not worth a chance for a fire hazard like that in your home. I hope the
garage is not attached to the house. Be careful anything can ignite and
cause fire or explosion.

 

exactly! and doubly especially so if theres a gas fired water heater in
the garage the van is in.

i fried the engine bay of an 81 mazda 626 many years ago because it had
a carb leak and i pushed it into the garage to work on it. once the
water heater 15 feet away kicked in, the fumes from the small puddle on
the ground instantanously combusted.