D722 OIL priming ???

Muggman

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Removed front cover and replaced fuel injection cam. Replaced gasket and replaced cover. NO OIL PRESSURE NOW. I think it should have done picked up. I forced primed thru sensor port, but still not putting out any oil. What's the next step?
 

North Idaho Wolfman

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Take it back apart and figure out what you left out, or what didn't get put in properly.
You not need to prime these engines.
 

Vigo

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So looking at a couple diagrams it appears the oil pump bolts to block behind timing cover, while oil filter mounts on timing cover itself. This means pressurized oil crosses from block to timing cover in at least two places. Given what youve said, the simplest answer is that the timing cover gasket is misaligned or torn and you have pressurized oil leaking from the timing cover gasket abd simply dumping back into the pan internally.

IF there is an oil pressure relief valve in the timing cover (dont know) and you had to pry on the cover anywhere near it, that could be an issue. I once had that happen, where I flexed the cover in such a way that it cracked the relief open and didn't let it reseat.
 
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North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
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Sandpoint, ID
So looking at a couple diagrams it appears the oil pump bolts to block behind timing cover, while oil filter mounts on timing cover itself. This means pressurized oil crosses from block to timing cover in at least two places. Given what youve said, the simplest answer is that the timing cover gasket is misaligned or torn and you have pressurized oil leaking from the timing cover gasket abd simply dumping back into the pan internally.

IF there is an oil pressure relief valve in the timing cover (dont know) and you had to pry on the cover anywhere near it, that could be an issue. I once had that happen.
It actually has nothing to do with the gasket it's three O-rings that seal the oil passages.

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Vigo

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B6100, B8200
Jan 9, 2022
595
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San Antonio Texas
Thanks for the clarification. I only looked briefly in google image search (not actual service info) and generalized based on my automotive experience. Since individual o-rings are even MORE likely to fall out of place while setting the parts, i think that's likely the prime suspect here.
 

Muggman

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Jun 11, 2022
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Removed front cover and replaced fuel injection cam. Replaced gasket and replaced cover. NO OIL PRESSURE NOW. I think it should have done picked up. I forced primed thru sensor port, but still not putting out any oil. What's the next step?
THANKS!!!! for the replys. It has been down a while. I got frustrated and decided to crank it. I had turned it enough that I thought it should have been bumping the oil pressure guage needle by now. I came in the house and got even more mad. I decided it would pressure up or sieze. Tightened the injector lines. By the time I had cleared the last air from injectors I had oil pressure. Must or had a air pocket.
 
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Muggman

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Jun 11, 2022
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Take it back apart and figure out what you left out, or what didn't get put in properly.
You not need to prime these engines.
Pretty sure I had it right, but when I had covid I ran a fever for 12 days. Yes 12. My short term memory is void. I have to continually secound guess myself. I thank yall for the replys.
 
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Vigo

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Equipment
B6100, B8200
Jan 9, 2022
595
340
63
San Antonio Texas
Sorry to hear about the memory symptoms, hopefully that passes. Glad you got your oil pressure up!

Silliest thing i ever did to get a stubborn engine to prime was use a tiny funnel to fill the oil feed passage to the oil filter, and then turn the engine backwards by hand to suck it across the pump and down the pickup tube. Slapped on the filter and started it up again and finally had oil pressure!

Ive also used a shop vac and a small funnel (shove it over the shop vac hose to make a tiny ‘tip’) to put suction on that same port while spinning the motor and had that work.

But generally all i have to do is lube up the pump with an assembly grease to ‘tighten it up’ enough to suck air, and it works on its own. Not always!!