Stuck on a Cummins ISX fuel pressure issue for 3 days before finding the real culprit
So I had this 2015 Peterbilt with a Cummins ISX come in last month, throwing a low fuel pressure code. I chased it for three solid days. Changed the fuel filter, checked the lift pump, even pulled the fuel lines to look for blockages. Nothing fixed it. Then on day three, I noticed a tiny crack in the fuel line right where it connects to the head, hidden under a plastic shield. It was sucking air but not leaking fuel. Made me wonder if I should have pressure tested the system from the start instead of just visually checking. Has anyone else had a simple thing like a hairline crack waste half a week? Or do you guys always pressure test first?