Shouldn't the filter be under pressure?

[Ratat98]

Hello all. Fix one problem and find another..
Lately my truck has been acting like it has been getting air in the system and I think I know where it is, but I pressed the Schrader valve in on the filter housing while it was running the other day and it sucked air in then the engine died. Shouldn't there be pressure here and not a vacuum???
The lift pump is fairly new. Wondering if I need a new one already...
Thanks in advance!

 

[austin92]

Should be pressure, not vacuum. I have a facet duralift and running it will hit the IP with a stream of fuel. Could be a clogged fuel filter. I’d change it first


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[The_Josh_Bear]

Yes there should be pressure!

Sucking air at the Schrader valve while running means either your lift pump is bad out of the box, or during install you didnt get the arm up on the cam lobe. It's pretty easy to tell when it's on, since the body of the pump will be pressed away from the block and its hard to get the bolts started.

The IP will pull its own fuel supply but not run as well, either.

 

[Ratat98]

Yes there should be pressure!

Sucking air at the Schrader valve while running means either your lift pump is bad out of the box, or during install you didnt get the arm up on the cam lobe. It's pretty easy to tell when it's on, since the body of the pump will be pressed away from the block and its hard to get the bolts started.

The IP will pull its own fuel supply but not run as well, either.

Oh I know I got the arm in the right spot. It was a pain... guess it's time to find another lift pump. Just changed filter a week ago also.

 

[Thewespaul]

The Schrader valve is on the inlet of the filter so even with a clogged filter it should puke fuel. Your lift pump is either bad or you have a restriction upstream

 

[IDIoit]

The Schrader valve is on the inlet of the filter so even with a clogged filter it should puke fuel. Your lift pump is either bad or you have a restriction upstream

you mean downstream, if you think of the fuel flow as a river
but im with this guy.
either a failed lift pump, which is not unheard of in todays market.
or you have a clogged pick up or fubared feed line