96 850 fuel leak with full tank

Post by **scot850** » 06 Jun 2023, 23:24

The car just keeps giving...........and not in a good way!!

The owners have just added that when the fill the fuel tank it leaks, but only when full. Now they only keep it at 3/4 or less.

What leaks on a P80 FWD fuel tank? Hoses, cracked pump plastic nut ring, leaking rubber seal? What else is up on top of the tank that leaks?

Thanks,

Neil.

xanthefin · Post by **xanthefin** » 06 Jun 2023, 23:38

Its known fault cracked breathing hose top of tank on these when aged. When i fill tip top it just comes out from there.

Others may correct me but this what i learned fron these. I have hose but still i havent changed it.

Post by **abscate** » 07 Jun 2023, 04:42

Open up the access port to check the top of pump. Dropping the tank on a FwD is easy once it is empty

NC855R · Post by **NC855R** » 07 Jun 2023, 04:56

Same here, was the top hose on the tank on mine. Would leak out after a fill up and stop after the tank level receded a bit. Following RobertDIYs instruction of drilling a hole to access one of the clamps.

xanthefin wrote: 06 Jun 2023, 23:38 Its known fault cracked breathing hose top of tank on these when aged. When i fill tip top it just comes out from there.

Others may correct me but this what i learned fron these. I have hose but still i havent changed it.

Post by **scot850** » 07 Jun 2023, 10:21

Thanks guys for your help. This was what I guessed and I'm going to get a camera up in there today for a quick look. That repair will have to go on the back burner and just not fill the tank all the way for a while. I have also seen the large black lock nut for the fuel pump crack and leaks from the seal gasket, but what you suggest sounds more likely.

I have not dropped a tank in a while on a FWD. My concerns on that is the joint is crusty at the tank for the fill pipe and I can't recall if you have to undo that to remove the tank or if you can drop the whole lot like on the AWD. I'll do some reading!!

Neil.

Post by **abscate** » 07 Jun 2023, 11:53

Remove the spring clip, work the gaiter into the fender space, and drop tank and fill pipe together.

Post by **scot850** » 07 Jun 2023, 13:03

Thanks abscate. I do that with the AWD, but it has been 7 or 8 years since I did that on a FWD!

Neil.

NC855R · Post by **NC855R** » 07 Jun 2023, 13:09

I did not drop the tank to replace the top hose. One side is pretty accessible to get the clamp off, the other side not so much, that is where the drilled hole comes into play to get a screwdriver on the clamp.

scot850 wrote: 07 Jun 2023, 10:21 Thanks guys for your help. This was what I guessed and I'm going to get a camera up in there today for a quick look. That repair will have to go on the back burner and just not fill the tank all the way for a while. I have also seen the large black lock nut for the fuel pump crack and leaks from the seal gasket, but what you suggest sounds more likely.

I have not dropped a tank in a while on a FWD. My concerns on that is the joint is crusty at the tank for the fill pipe and I can't recall if you have to undo that to remove the tank or if you can drop the whole lot like on the AWD. I'll do some reading!!

Neil.

Post by **Chuck W** » 07 Jun 2023, 19:29

This is what leaked on the top of the tank on the wife's car. (Also caused the perpetual P0455 code) Chewed up vent hose.

Post by **scot850** » 07 Jun 2023, 20:50

I stuffed my camera up there but not far enough. I may have to take the cover off and have a look with the camera from above.

Thanks Chuck!

Neil.