2001 V70 Fuel filling problem Topic is solved

altalake · Post by **altalake** » 20 Sep 2015, 16:16

Fuel filling problem on a 2001 V70. Any flow rate faster than 15 to 20 minutes to fill the tank results in fuel backing up in the filler pipe and shutting off the pump. In some cases it doesn't shut off the pump and fuel splashes back out. This problem started around June on a long highway drive. The issue is not affected by air temperature, elevation, fuel brand/pump design or pump nozzle position.
What is not causing it is
1. Obstruction in fuel filler pipe - checked with borescope.
2. Obstruction in tank venting system - all hoses and valve removed and checked, good air flow through charcoal filter. Even with all these things disconnected (no small amount of shop labour involved) this did not change the filling problem.
Most of the other references to this issue on forums have involved obstructions in the EVAP system - dirt, insects, faulty shut off valve - but it's none of these.
Mechanic and I suspect the culprit is the anti-siphon (or whatever it is called) flap valve right at the entrance to the gas tank. Not easy to get at. Not a known issue (not the same as the Volvo bulletin for 2003 models where they show changing a pipe clamp to solve the problem).
Ideas? Fixes? NB. This car has a plastic fuel tank and fuel pump was replaced by a dealer 1 year ago.

altalake · Post by **altalake** » 23 Sep 2015, 20:14

Fixed.
Pulled fuel pump just far enough to see flap valve. It seemed to move freely. Still suspicious of it, I reached in and inadvertently popped the flap valve off its mount (surprisingly easy to do). Flap valve is now in the bottom of the tank somewhere. Filling problem gone.
Still curious as to what caused this. Maybe somebody tried to siphon gas and damaged the flap valve. Maybe not.
Alternative to this accidental repair would have been dealer replacement of fuel tank - 9 hours shop time @ $200/hr and about $3,000 for tank (plus taxes) - more than the car is worth.

Loopie · Post by **Loopie** » 21 Feb 2016, 23:14

Just picked up an '01 V70 X/C the other day....fuel gauge reading almost empty...fill nozzle at the station kept kicking off after only 35-40ltrs or so. I only gave it a 10sec pause about half a dozen times then left it to see what was up...figured the fuel gauge was probably not working and the tank was actually full.
Nope. It looks like the gauge works....as it now reads about half a tank.

Hmmm....

altalake · Post by **altalake** » 16 Mar 2016, 13:23

This sounds like a different problem from the one I had. I could always fill my tank - it would just take a really long time. Really long - about 15 to 20 minutes. In your case it might be the venting - the problem which most people report and can be an easy fix if it's just the filter at the end of the vent hose. I wasn't so lucky.

pbierre · Post by **pbierre** » 15 Apr 2021, 19:30

I believe there is a filter inline in the refueling vent hose. Not sure where it's located on '01V70. On my '13 XC70, it's at the top end of the vent pipe, where it "Ts" into the fuel filler throat.

I backflushed it with throttle cleaner fluid, with a chaser of 100 psi compressed air. That did improve things. I had the same problem.....fuel pump would refuse to pump unless at the lowest flow rate.