2000 V70R - AWD fuel/emissons pipe routing

[Maestrours]

Thanks Neil ! Is the check valve in this plastic case too ?

[scot850]

No. I'm not sure what you mean by the check valve. The roll over valve is up beside the carbon canister above the rear axle and near the fuel filter.

Roll over valve

2000 V70R AWD Fuel and Emissions pipe routing 041.JPG (255.96 KiB) Viewed 414 times

You can see the rollover valve to the right of the carbon canister and forward of the fuel filter here. It is attached to the carbon can by the flat 'U' pipe from the carbon canister. The pipe to the vent pipe comes out of the rollover valve. You can see it running under the black pipe to the right of the valve and just before the valve as we look at it.

There is another valve which I can't recall it's roll in the system. It is in front of the carbon canister and below it. It is impossible to get to without dropping the axle. It is the one in the picture below. The carbon canister is above it. The red tape is below it.

2nd valve.

2000 V70R AWD Fuel and Emissions pipe routing 074.JPG (307.69 KiB) Viewed 414 times

Then of course there is also the FPR as well on top of the RHS of the tank.


Neil.

[Maestrours]

Sorry I wasn't clear. I assume that there is a one way valve for the tank venting, as overpressure is going through the canister, but negative pressure is compensated by the venting ?
Is this function assumed by rollover valve ?


Am I right or overpressure can go out through the venting too ?

[scot850]

It is closed only when the system is running the emissions test or the car is upside down! They can jam shut and not allow the system to vent making filling the tank a pain, but could cause a level of vacuum in the tank as the tank is then drawing against a vacuum.

Neil.

[scot850]

This is the fuel pressure sensor (which is NLA) and it the one in my 2nd picture above just above the red tape. There is also the 2nd pressure sensor/regulator on the return fuel line above the fuel tank but operates on the tank to engine line as well.

https://www.volvocarstorontoparts.ca/p/ ... 55870.html


The link below gives you most of the system with exception of the fuel lines:


https://www.volvocarstorontoparts.ca/a/ ... 43482.html

Fuel lines:


https://www.volvocarstorontoparts.ca/a/ ... 76983.html

Most if not all the fuel lines for AWD P80's are NLA.

Neil.

[Maestrours]

Thanks ! So I assume the vacuum i can feel when I open my gas tank to refill is due to this valve stuck closed. I'm afraid it will be complicate to repair it as it seems very hard to access to this part.
I'll give a look and try to push air with a compressor on the filter but if it fails i might do a hole on the gas cap...

[abscate]

It’s not hard to access. The wheel liner comes out with plastic 10mm hex nuts, taking the wheel off gives you good access to the parts

[scot850]

The roll over valve is not too terrible to get to. Carefully check the pipe from the carbon canister is not perished. My Volvo one failed in about 4 years and the car spent half that either not running or in the garage. When I got an emissions leak I could not see the crack as of course it was on the top which I could not see. Volvo smoked the system and found it. I was disappointed it failed so quickly.

Good luck.

Neil.

[Maestrours]

The roll over valve is not too terrible to get to. Carefully check the pipe from the carbon canister is not perished. My Volvo one failed in about 4 years and the car spent half that either not running or in the garage. When I got an emissions leak I could not see the crack as of course it was on the top which I could not see. Volvo smoked the system and found it. I was disappointed it failed so quickly.

Good luck.

Neil.

Oh. What was the consequences of a canister failure ? I thought it might just evaporate more fuel outside of the engine without consequences for itself ?

[abscate]

The tank is open to atmosphere through the carbon canister so you don’t smell fuel, it’s caught in the carbon. The J hose connects the carbon canister to the canister shutoff valve , which is open normally.

When the purge valve opens, it pulls air through the canister shutoff valve and J hose , purges the canister of gas , and dumps it into the intake manifold for burning. A cracked J hose won’t change that function.

When the system tests itself , the shutoff valve closes and the system performs a bunch of tests pulling vacuum on the tank and seeing how long it holds, etc. a cracked J hose will cause those tests to fail and the warm glow if the Check engine light ( in Canada , an engine icon) ensues , indicating a P04xx code