Hi.
Just replaced a piston in this truck, and I just saw that the resovoir for the oil will not stay full, any ideas? The truck will not run now.

 

How fast is it going through oil?
Are there any leaks that you can see?
white smoke while running?
are you checking the oil in the pan or in the HPOP?

 

Did you have any parts left over ?....JK...

Is it a possibility you nicked an ORing on an injector ?...

 

No, no parts left over, for a change, lol. I replaced the o rings when I was putting the motor back together after the piston went in. For a while, it would crank, and run, then it would crank, run for about 10 to 20 minutes, and quit for a few hours, then it would do the crank, run 10 to 20 min, and quit. I had oil pressure, at one time after putting it back together, but I was messing around with it, and realized that the resovoir is empty, and won't stay full. Anyone know where I could get breakdown pics of this particular motor, so maybe I can identify something that was lost? Thanks.

 

Like this ?...



Are you sure you assemled the LPOP properly?...

 

Go to Engine -> 7.3L -> Components

1997 F-250/350/Super Duty Workshop Manual

 

Ok another question. I took the oil filter off, and cranked it over, nothing came out, so I think it has something to do with the oil pump, not the HPOP. Is there anyway you can prime that low pressure oil pump?

 

If you had the gears in the LPOP apart ,,they only work one way...

 

No, I did not take the gears apart in the LPOP. When I took the motor out of the truck, I had it sitting on it's side for a couple months until I could get the parts to put it back together. After I put it back together, the truck started and ran for about 45 minutes, then quit. Then it would run for about 10 to 15 minutes, ( after being started on starting fluid ) then cut off, and would not restart for quite some time afterwards, even with starting fluid. I take it that there is no way to prime the LPOP?

 

Cracked pickup tube ,or injector O rings ,,you don't need to prime the LPOP....

A worn front cover can cause this also ,,,,,,

 

Hey guys this may sound pretty dumb and doesnt really belong here but, when people say "Big Oil" does that mean having a high pressure oil pump?

 

These engines have both a low and high pressure oil pump, "big oil" is referring to the HPOP.....it fires the injectors.
The LPOP supplies oil to the HPOP plus all the other engine internals ie. crankshaft, rods ect.
LPOP = 60 psi
HPOP = 3000 psi

 

Wow that much of a difference huh? never knew that. So by replacing the HPOP with a bigger/better pump is how you get the phrase "Big Oil"?

 

LPOP = 60 psi
HPOP = 3000 psi ( really 3000? or 300? )
That HPOP seems like a lot, but then again, I guess it would be for the job it does, huh?
Wow, thanks for that information. Is there a way to check to see if it is the pickup tube or oil pump, w/o removing them? Just wondering, I would hate to have to remove the motor for the 3rd time, to replace the pick up tube. Thanks.

 

You can check for a cracked pickup tube by adding 2 qts more the the CC & raise the rear of the truck....
The oil pump is a easy R&I ....