The gas tank on my 2000 Park Ave is leaking when filled to capacity. I removed the access panel in the trunk to expose the fuel pump and found that the retaining ring that secures the pump and the ring that engages the retaining ring are completely rusted out. Replacing the gas tank appears to involve removing the entire rear suspension. I really don't want to do that! Does any one have any suggestions for repairing the tank without removing it?

I am sorry to tell you, that is your only recourse......maybe talk to GM, since it is a safety problem, may get some partial payment......call GM Customer Service....

I am pretty sure that is a plastic tank, correct?

Ran into this once, as I was backing out the locking ring, the ring that was imbedded in the plastic came out with it...had to replace tank....

I did a fuel tank on a 96 Park Ave, never touched the suspension. So... I can't see how this applies to a 2000.

Yes, it is a plastic tank with the steel ring embedded in the plastic to clamp down the retaining ring. The tangs on the tank that engage the retaining ring have rusted off completely. I bought a new retaining ring, I am considering screwing the ring to the tank with stainless steel screws. The ring was only $13.00, worst case it does not work and I have to replace the tank anyway.

Mike, The 1997 thru 2005 Park Ave has a rear sub-frame that mounts to the body with cushions similar to those used to mount the engine cradle in front. They are generally rusted out , difficult to remove and need replaced. In my case the rear subframe is rusty and will likely need replaced as well. If I can leave it alone it will likely last a couple more years but if I remove it, it will likely fall apart.