When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I have a 2002 Ford F-250 7.3 I was changing the front cover on my Ford F-250 finished all up then I went ahead and got a new low oil pressure pump but all of a sudden the truck is a no start and I have checked the hpop reservoir and it has no oil I can fill it up and the truck will start and stay running but it shows I have no oil pressure unless I’m above 1000 rpm’s once I’m above 1000 rpm’s the oil pressure will go back to normal and the truck will run just fine but once I come to a stop and I sit at idle the oil pressure will go back to nothing and the truck will start running like crap the high oil pressure pump is less than a year old and I’m totally blanked on what it might be
Sounds like the oil anti-drainback valve isn't working properly. Noted as Short Circuit Device in the illustration below. Thought I had a pic of it from above but can't find it. IIRC it's a 3/8 square drive plug with a simple ball and spring check valve underneath.
When you installed the new low pressure pump did you soak it in motor oil like described in the instructions? If not the the pump could likely be air locked. No amount of cranking will prime the pump either. If that does turn out to be your problem the only way to get it primed is take it back off or raise the rear of the truck high enough to let the oil reach the pump.
After sitting overnight does the oil level in the HPOP reservoir go down?
And welcome to FTE!
You homed in on that quick enough.
Originally Posted by udsuth78
When you installed the new low pressure pump did you soak it in motor oil like described in the instructions? If not the the pump could likely be air locked. No amount of cranking will prime the pump either. If that does turn out to be your problem the only way to get it primed is take it back off or raise the rear of the truck high enough to let the oil reach the pump.
But if he's got the engine running, wouldn't that eliminate that?
But if he's got the engine running, wouldn't that eliminate that?
Not if it only runs long enough to drain the res. Embarrassed to say I learned the hard way on this one. Mongo no need destructions. I screwed with it for like 2 hrs before I threw in the towel and just pulled it off and did it right.
One thing to learn about these monsters, never rush the process! Any one of us can tell you how rushing to the light in the tunnel lets you miss a crucial step in the process!
I just hope it is fixable , take it apart and start over!
Also looking at the illustration, would you not be able to fill (prime the Lpop) as you assemble?
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Slideshow: The VelociRaptor Expedition gains a lift, upgraded suspension, Brembo brakes, and trail-ready equipment while retaining the stock 440-horsepower EcoBoost V6.
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.
