Look to this location after you’ve inspected the oil discharge hose fittings, the rear plug and/or the “non-serviceable” plug. 7.3 HPOP Rear Plate O-ring Seal LeakĪ leaking o-ring in at the HPOP rear plate is very uncommon. Replacing the non-serviceable plug isn’t trivial - it requires fuel bowl and HPOP removal before you can replace it.

Though the “non-serviceable plug” is a very uncommon leak, it can happen. If you find even a small amount, don’t take chances - a preventative o-ring change on an HPOP rear plug leak will save you a walk home. Run your fingers around the head of the plug and see if there’s fresh oil. Sometimes the plug on the rear of the HPOP leaks (See location in diagram above). The HPOP fitting o-rings ( Amazon Link) are a well-known failure point and cause for a leaking HPOP.ĭo yourself a favor and if you see even a little oil leaking around them, perform some preventative maintenance-change the o-rings before they fail and dump all your 7.3’s engine oil into the valley. 7.3 HPOP Common Oil Leak Locations Leaking 7.3 HPOP Oil Line Fittings It’s where numerous “leaks” start and it could save you a long walk to the nearest service station.Ī lot of oil in a short amount of time points to the EBPV (Exhaust Back Pressure Valve) on the turbo pedestal or more-likely the HPOP line fittings. It’s a good idea to check the valley frequently. Down below 500psi of startup pressure, and they might not fire at all. If the pressure’s low, they won’t operate efficiently. The injectors actuate by using high pressure oil in the oil rails. Other symptoms include a gradual loss of power due to lower pressure from the HPOP’s oil delivery system. The reservoir should have oil all the way up to within 3/4″ to 1″ from the top of the inspection plug. You can check for slow oil leaks from the 7.3 HPOP by checking the HPOP reservoir level (With the engine OFF!) So pull over immediately and inspect your engine valley for oil. But, by the time a CEL comes on, you’re about to start walking. We’ll detail them below… 7.3 HPOP Oil Leak Symptoms HPOP Causes a Check Engine Light (CEL)Ī leaking HPOP O-ring won’t necessarily throw a CEL or cause noticeable drivability problems until enough oil is lost to reduce flow to your 7.3 injectors. Still, there are other HPOP leaks that can rob your engine of power or leave you stranded on the side of the road. The fittings “click” into the HPOP and the heads and require a special tool to remove and reattach. The most common 7.3 Powerstroke high pressure oil pump (HPOP) leak happens when one or both of the HPOP O-rings on the oil line fittings fail.

6.7 cummins rear main seal leak