Fuel pouring out from under car when refueling.

[Agentlongwood]

My car is a 99 GTP and I recently purchased a fuel pump (ZZP350) and I've had it installed since I got it about a month ago. It works great but a few days ago I ran into a problem. I used the big o-ring that the pump came with that seals the canister assembly to the tank itself and now it is not sealing properly. I had no problems for the month or so since I installed it but now when I top off the tank fuel pours out of the gap between the canister assembly and the tank. I did not remove the canister or mess with anything at all, it just decided it didn't want to seal anymore. I checked and the snap ring that holds the canister assembly in place is installed correctly. I had a friend drive around while I was in the back seat looking through the trap door, and I could see fuel coming out when we went around corners and such. It is definitely coming out as a result of the canister assembly not sealing to the tank. Is there something I did wrong? Was the big o-ring that came with the kit supposed to be used there? Anyone seen this before? I've never heard of it happening so I'm at a loss and any help would be greatly appreciated.

[MoarkatsINmuhtrailer]

Did you replace the old oring for the one zzp sent you?

[Agentlongwood]

Yes, I did.

[MoarkatsINmuhtrailer]

Did ya lube it?

[Jackblack99]

My car did the same thing. I didnt put a fuel pump in like you did, but mine would leake like that. Yes the seal was supposed to go in there. I have seen the seal roll off the bottom of the canister and cause a leak. Its odd that yours didnt leak for a month then just started leaking. Sounds like you need to pull it out and see whats going on.

[Agentlongwood]

I did not lube the o-ring before installing. Never even thought about it. What kind of lube is used in fuel tank areas? I pulled the canister and checked it out and I couldn't tell that there was anything obviously wrong. And yeah I thought it was weird that it was fine for like a month and then just stopped sealing. How does that even happen?

[MoarkatsINmuhtrailer]

I use plumbers grease so it sits properly. Squeeze it so it folds and see if it cracks anywhere.

[Agentlongwood]

The 1 snap ring is the only thing the holds the canister down in the tank right? Theres not like some secondary mechanism thats supposed to hold it in place is there?

[MoarkatsINmuhtrailer]

Nope, just the b1tch on the top.

[gmpowered]

Just the snap ring, on the pump the rubber o ring has to be in the right groove (upper last or top IIRC) of the canister to seal properly, to lube it use Vaseline.

[TexasTanker19kilo20]

This happened to me also, the old o-ring had been pinched and leaked. I got a new o-ring and lubed it with dielectric grease, it held in place. It was a PITA to get that snap ring on though.

[Agentlongwood]

I use a pair of needlenose pliers and the ring doesn't give me a huge amount of trouble. For a sec I was like "Oh god its too easy it must be broken" lol

[Agentlongwood]

So I opened it up again and checked out the gasket. Visually it looked good to me but who knows. I lubed it up with some vaseline and reinstalled everything, problem persists. Nobody has had an issue where it was something other than the o-ring have they? I don't even know what but something different in that same area. Almost afraid to ask lol.

[BillBoost37]

FWIW I always lube with vasoline and never have a sealing issue.

Why vasoline you ask? Because it melts/breaks down in almost anything w/o any issues.

[MoarkatsINmuhtrailer]

I think it's gotta be the assembly is cracked or something.. I'd pull it out and inspect the hell out of it