Fuel Pump Seal .... glad I checked!
 

Hi all,

I had recently convinced myself I could smell petrol around the rear drivers side .. more pronounced after filling up but often just after using the car.

You may have already seen threads about the rubber seals fitment for both the Fuel Pump (UK drivers side) and the infamous Fuel Filter (passenger side)

Here's what I found....

Armed with a replacement seal, I removed the rear seat cushion and the inspection panel under the cushion, drivers side.

In the first picture all looks ok with the fuel pump fitting, but it certainly wasn't. The metal retaining ring AND the pump were simply there because of gravity! They were both movable and lift-out-able by hand with no effort at all :eek::eek:

I think what has happened is that at some time in its life the pump has been removed. When refitted, the rubber seal had been put on the underside of the pump only and NOT fitted around the collar of the fuel tank port that the pump fits into. The seal is shaped to do that.

So the whole seal had been "compressed" in between the underside lip of the pump and the top of the fuel tank port. The metal ring which screws down to seal and hold the fuel pump down simply could not hold it all together.

Or if it did initially, it had popped up and off its thread at some time under the strain. Whoever fitted it must have REALLY struggled to screw that metal ring down into place!

In the second picture, with the metal ring lifted off, you may be able to see that the fuel pump is resting about 4mm higher up from where it should be sitting, because of the extra thickness of the seal underneath it.

Anyway, fitting the seal correctly around the collar / lip of the fuel tank port, it all settled down into place and the metal ring can do its job ok now!

So folks, always make sure the seal on the pump, and the filter too, gets fitted in the right way!

Incidentally, it's fairly obvious which way up the seal goes even though the aftermarket seals don't have the "This side down" markings that the originals do. See the third photo for reference.

For completeness I checked the Fuel Filter seal was fitted ok on the passenger side, and all good there. Phew.

No more petrol smells now!

This post ended up longer than I'd planned, but hope it helps.

Happy Roving!

John

Posted about this a couple of months ago, exactly the same problem now sorted. This was on the Moonstone V6.

In your third photo (below) -

https://the75andztclub.co.uk/forum/a...1&d=1551963364

- I assume the seal is standing in the correct orientation up/down. This is an important point to emphasise, especially if the current seals don't have the BMW brand and the 'This side down' wording on the face that goes into the tank.


TC

Hi TC

Yes, just to confirm to anyone reading, that picture indeed shows the seal the "right way up".

I think I noted that from an old thread on the Fuel Filter side (I think it was one of yours I'm sure) but thought I'd add to my post too.

Regards

John