So the cap on the water/fuel separator keeps popping off. Replaced cap an it blew off again. So replaced filter an cap this time an made it a few more kms before popping the threads on the cap an its leaking again. Any ideas???

Collapsed or plugged fuel line from canister to VP?  You have a section of hose between the two steel lines that run between the two? Cap threads stripped/worn?

Edited February 5, 20205 yr by Blueox01

Somehow you are developing too much pressure.  (or too much temperature)

 

You may actually have a threaded adapter on the lift pump to fuel manager banjo bolt.  (I know mine and my brothers 01 had them there)  (if you don't add one or move the one from the VP there, it will help diagnose your problem)  this would let you compare the pressure before and after the filter.  This would help you diagnose the issue.  I see you have an Aux tank, so you have something special for a lift pump system.  I think somehow you are getting some high pressures.  Another thought may be the fuel heater.  Could it be heating without control and getting the fuel there too hot?  This would weaken the strength of the fuel manager cap.  

 

GL

 

Hag

Yes definitely seems like too much pressure building up. Everything seems to b flowing good from canister to VP. No clogged lines. Could lift pump b faulty, an sending too much fuel?? Trucks going to the shop tomorrow anyways, so i guess time will tell. 

How much  fuel pressure do you have?

No gauges...

No gauges is no excuse.  Unless someone has fubared it, there is a schrader valve on the lines from the factory. 

 

Test port here (between lift pump and inlet to fuel manager, circled in red)

 

 

And a test port here (inlet to VP circled in red)

I don't remember this exact size, but most of the standard GM pressure testers will screw right on.   both of the zone stores "rent" fuel pressure test systems.  I.E.  you buy it, use it, and return it for a full refund.    If you want to see it while driving, buy the pressure test system and extend the hose so the gauge comes out of the hood right near the wipers.  Works great for testing.

 

GL

Hag