A couple days ago my gauge started reading erratically. when I first noticed it it was reading 1. 5 psi, I stopped the truck, shut it off and bumped the starter and got 2. 5psi. On the next start, it was back to the normal reading of 6. 5 psi until I pulled the pressure down @ WOT and stuck at 2. 5 psi again. Now the gauge might get up to 1. 5 psi after the truck has been running for a little while. Could the lift pump be dying or is my gauge TU? The gauge is a mechanical DiPricol that I put coolant in the line after the isolator, there are no visible bubbles in the line and the coolant is still green so I don't think the Isolator is bad. Will a lift pump go bad intermittently like this? I am going to the local Cummins place to put a gauge on it this morning
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