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HPO Questions / help

1078 Views 6 Replies 4 Participants Last post by  4micaman
Hi all, I'm just going to get straight to the question. I have the pump deadheaded with a guage, I just replaced the IPR and cannot get any high pressure, only able to see about 150 psi. I have seen threads where they say the hpop doesn't just go bad, so that leads me to believe it's something else. Please, any suggestions would be wonderful.

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Make sure the oil level in crankcase is full as well as the HPOP res and the oil psi gauge on dash shows oil pressure. There could be debris in the IPR cavity even though you replaced IPR

To isolate the heads as a potential large leak: 1) Remove the line from the right head and cap with a suitable plug. 2) Remove the left-hand line and connect an oil pressure gauge capable of reading 3,000 psi or greater to it. 3) Crank the engine while watching the gauge for actual pressure. If the reading is low, the problem lies in the high-pressure pump or the IPR. But to determine which is the guilty culprit, you first need to replace the IPR to evaluate. If that doesn't correct it, the pump will need replacing.

IPR pump can go bad / not unherd of. Also I have seen where the HPOP was installed and the gear was not installed correctly and caused low HPOP
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I have 3 of these OBS trucks and one had the same problem you have. I ended up replacing pump and problem solved. We deadheaded pump with gauge and sure enough could not get the pressure,replaced IPR and still no good. Replaced pump and good after that.
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