blazen71
Veteran Member
Hello all. Something I've been thinking about with the B5.5 TDI's. Will they run if the in-tank lift pump fails? Does the tandem pump suck fuel if the in-tank pump fails?
I have replaced the fuel filter but filled the new one with PowerService first. I had no issue with starting after the change.I have seen them run fine with no issues, but if you replace a fuel filter or open the system in any way, restarting will be a long adventure.
I have two I can think of that have run years without the lift pump, discovered after a filter change. I have seen reports of problems due to lack of lift pump, but have not experienced it without other underlying fuel system integrity problems.
We used to put lift pumps on the old rabbit diesels with injection pump seal issues. They would run fine, but bleed back to the tank overnight as the seal sucked air.