I just like to say that my truck is running better than it ever has, since installing the DTT filter and APPS reset ... definately worth the effort! Now I'd like to maintain it in this condition!

The question at hand is: I've been fighting this fuel tank vacuum problem for a while. How does the little valve doohickey work that is on the fuel sending unit? I have attempted to clean it out, but have not had success. Can I use a hand pump or vacuum tool (the type for bleeding brakes) to try and clear it?

 

Piperca,
I had the same issue with my '99. I have not taken the time to look into the roll-over check valve. I just looked for the red cap on the vent and when it was not there I put a screw in the filler cap vent to hold it open. I just found one that threadted right into the hole. It has been there for two years and is fine. It is large enough that it will not cause an issue if it was to fall out. There was someone (don't remember who) that said they used an air nozzle and blasted it once and it cleared out.??? Some day I 'll look into fixing it properly but I have more pressing things to take care of right now.

Randy