Paccar fuel filter doesn't stay full

[Pete379]

I have that same filter setup. The paccar filter assembly mounted vertically on the frame should be full of fuel to the top. Pull the filter and take a look where the pickup is at. It looks like it would be right at the level that your fuel is so that would explain why no hard starts it’s getting fuel but there’s something wrong. Possibly a check valve or something. I never experienced this problem but you have to address it. Does it look like that while the engine in running or only when it is off?