I just replaced my fuel pump with a new Delphi I bought on line. On filling up with fuel I noticed a leak under the car so back into the install and tighten the pump retaining ring some more. It surprised me in that I was able to give it over an extra 1/4 turn- my bad I figured. Next day I notice another leak. Inside again but this time I pull the pump to see if I'd buggered up the sealing ring. The ring has fallen into the tank but upon examination, it's soft and swollen. Fortunately I have another seal from the fuel filter change out so I'm able to repair it. Looking closer at the old/new seal I see it says 'diesel fuel only' on the seal. Somehow the seals must have been mixed at Delphi? New one on me. Could have been a real problem if a fire was the result though. Might be a wise idea to look at the replacement seals from now on.
Hal

 

I remember a lot of concerns in the past about replacement seals being marked diesel fuel only, even ones from MINI dealers. This was posted by one of the vendors. https://www.northamericanmotoring.co...ml#post4208252

Maybe ECS, Way, or another vendor has more info to clear up the confusion on the seals being possibly mis-marked, or what the correct part number is for gas seals.

 

+1 Yep, its the same seal. What you have to do is seat the new seal and then twist the ring down, some people light grease the seal if its tight.

 

Well the seal I have swelled up enough that there was no way it would fit. It is at least 1/2" larger in diameter than the other seal. It has also become 'mushy' and soft. I also lubed the seal when reinstalling the fuel pump and all worked as it should.
Hal