What's this part ?

Post by **manovlov** » 08 Sep 2026, 01:40

Hy Guys,

I continue to discover my 850. Behind the fuel filter there this part circled on the picture. To what does it serve to ?
There is 1 connector hard plastic hose on each side. From the back to the front of the car, one of them is "taken" with the fuel hoses and run under the engine. What is it for ?

Manov

Post by **misha** » 08 Sep 2026, 04:05

Should be roll-over valve...inside of rear right wheel...can't really see clearly.

Usually...on later cars with m4.4 there should be a FPR,but yours with LH Jetronic is on fuel rail.

Btw....that fuel filter isn't secured properly on it's bracket and those fuel lines from fuel filter are not safe at all.

Post by **manovlov** » 08 Sep 2026, 05:30

misha wrote: 08 Sep 2026, 04:05 Should be roll-over valve...inside of rear right wheel...can't really see clearly.

Hy misha,

You're right about the location of the part, behind the rear right wheel.

misha wrote: 08 Sep 2026, 04:05 Usually...on later cars with m4.4 there should be a FPR,but yours with LH Jetronic is on fuel rail.

I've got a FPR on the fuel rail just behind the fuel rail. So what could this part be then ?

misha wrote: 08 Sep 2026, 04:05 Btw....that fuel filter isn't secured properly on it's bracket and those fuel lines from fuel filter are not safe at all.

I will secure that this afternoon.

Thanks for the advice.

Manov

Post by **misha** » 08 Sep 2026, 06:40

Roll-over valve.
It prevents fuel leaks from the tank in case of an accident where car could end up on the roof.

Post by **manovlov** » 08 Sep 2026, 08:15

misha wrote: 08 Sep 2026, 04:05 Btw....that fuel filter isn't secured properly on it's bracket and those fuel lines from fuel filter are not safe at all.

misha, about the fuel filter, i had to fix it like this and block it by its lip, because the body of the fuel filter was a little smaller than an original one. I think it's time to replace it by a good OEM one.

Thanks again misha.

Manov

Post by **misha** » 08 Sep 2026, 08:20

What do you mean?
Bosch,Mann,Mahle(Knecht),Delphi fuel filters are all the same size as oe Volvo.

Post by **manovlov** » 12 Sep 2026, 00:44

misha wrote: 08 Sep 2026, 08:20 What do you mean?
Bosch,Mann,Mahle(Knecht),Delphi fuel filters are all the same size as oe Volvo.

When i screw up the filter in its bracket, the filter is not hold enough, that's why i said i was screw it from the FF lip. Anyway, i will replace it so, i will install a BOSCH or MANN one.

Manov