Getting an oil pump primed

[flatie46]

OK...It's like this see... all the leaks that my good ole AMC 304 had were getting on my nerves. So I bought a bunch of gaskets (timing cover, front and rear seal pan gasket and a few others and I spent some quality time under my Jeep. I think I got it sealed up pretty good. Whilest I had the timing cover off I moved it several times, put the crank seal in and so forth oil would spill out here an there. I didn't much worry just wiped it up and went on about my biz. After getting it all back together, it fired right up. Oil press went to 20psi for a couple sec the to nothing. I haven't been able to get it to prime up since. Last night I packed the pump full of vaseline and it still wouldn't prime. I rebuilt this pump a couple years ago and toleranced it, it has run 60psi cold since, it will drop to 20psi when really hot at idle. I don't think the pump itself has a prob other than getting it primed. Anybody got a suggestion or a trick for this? I may try the vaseline trick again. It worked great a few years ago. Maybe I should have got the baby fresh scent.
Thanks in advance

Flatie 46

 

[greg92jeepxj]

Hey Mark , first I'd like to wish you and your family a happy Thanksgiving with all of Gods blessings . Sorry to hear about the oil pressure problem . Been kicking it around for a few minutes and I know your no rookie so you know your jeep and been around engines for a long time so I won't take up a lot of time with questions . I know you can put an engine back together so been thinking from when I owned an AMC 360 and did a rear main seal and had to reprime the engine . I did as you did , packed the oil pump with petroleum jelly . It worked , so I trying to figure what might not be going your way . Only thing I know is that if the plate where the gears are dosen't seal well you loose pressure and prime . I don't think you disturbed the oil pick up so it would not have lost seal either . Only other thing I can think of is the gasket seal on the timing chain cover ( front cover ) where the block has that hole that draws oil from the pick up .
I know you said you moved the front cover several times , do you think that would have somehow had anything to do with this problem ? You had pressure for about 30 seconds resulting in 20 psi , but somehow the pressure was lost suddenly and it sounds like the prime was lost due to seal between the pick up and the oil pump . I feel bad that after all the hard work and well meant effort , there is this problem . Just sorry you'll have to get back into it . Real sorry .
Hope this helps and I hope the problem is rectified soonest with the least effort and time .
Best of luck brother . Greg

P.S. - I would say , as your already thinking , try to prime again. I'm sure the proper space between the plate and gears is adequate to make proper pressure.

 

[jps4jeep]

If your confident that the pump is good? With the valve covers off, prime the motor, if your getting oil to the head, probably a bad guage or sending unit (manual vs electric).

Since 99% of the engines that come my way now are LS based, been a long time since I was inside a AMC V8, but the oil pump on the timing cover, correct?
What are you getting for gear end clearence? IIRC should be about .002-.003. Perhaps a thinner cover will get you to that .002-.003 clearance.
I have heard of people having to machine the cover to get the gears high enough to end up with proper clearence to improve oil pressure, but generally in these situations it is just poor oil pressure rather than lack of oil pressure.

 

[flatie46]

Thanks for the reply guys, I've been pretty busy and haven't had a chance to get back to it but I've been thinking about it. Last time I did the vaseline trick was when I rebuilt my oil pump a couple years ago. Then I used a drill to prime it instead of just cranking it. As a good friend pointed out, the drill turns much faster than the cranking speed of the engine and may be the factor. I'm going to give it anthor try maybe friday, I've got a gutted distributor I'm going to attach the drill to an see what happens.
Jps4jeep- The pump was good before I took it appart and the gauge seemed ok so I'm sure it's a prime issue. I pulled a valve cover while letting it run briefly and didn't see anything. I had between .003 and004 when I built the pump. The cover was scared under the gears a bit but all in all it's worked great up untill now. 60psi cold and 20psi at hot idle.

Greg, thanks for the confident words and I wouldn't consider myself a rookie but I am subject to brain flatchulence and brief dumb arse moments. It drives me nuts when I have a problem like this and can only work on it here and there a few min at time. We're pretty busy at work and been pulling alota of OT but maybe this weekend I can sort it out. I had put a new front cover gaskett on and felt good about the seal. I think me moving the cover around spilling oil out of the pump here and there caused this. (See dumb arse moment above)

Thanks for the help guys and Happy Thanksgiving to both of ya and all on the forum. Now to work on the 10lbs I plan to put on before monday!:roll:

 

[greg92jeepxj]

Thanks for the reply guys, I've been pretty busy and haven't had a chance to get back to it but I've been thinking about it. Last time I did the vaseline trick was when I rebuilt my oil pump a couple years ago. Then I used a drill to prime it instead of just cranking it. As a good friend pointed out, the drill turns much faster than the cranking speed of the engine and may be the factor. I'm going to give it anthor try maybe friday, I've got a gutted distributor I'm going to attach the drill to an see what happens. Jps4jeep- The pump was good before I took it appart and the gauge seemed ok so I'm sure it's a prime issue. I pulled a valve cover while letting it run briefly and didn't see anything. I had between .003 and004 when I built the pump. The cover was scared under the gears a bit but all in all it's worked great up untill now. 60psi cold and 20psi at hot idle. Greg, thanks for the confident words and I wouldn't consider myself a rookie but I am subject to brain flatchulence and brief dumb arse moments. It drives me nuts when I have a problem like this and can only work on it here and there a few min at time. We're pretty busy at work and been pulling alota of OT but maybe this weekend I can sort it out. I had put a new front cover gaskett on and felt good about the seal. I think me moving the cover around spilling oil out of the pump here and there caused this. (See dumb arse moment above) Thanks for the help guys and Happy Thanksgiving to both of ya and all on the forum. Now to work on the 10lbs I plan to put on before monday!:roll:

I think we all have them moments , just unfortunate though . Sorry about the hard long days working but the OT is always good the following week $$ ! I think another Vaseline pull will get results , especially the old drill method on the pump shaft . An old distributor fashioned as a primer drive is the way to go , that way you don't have to spend on the right size priming rod for different engines . I got lucky , one I bought for a SB Chevy fit a 3.8 Buick and would fit a AMC V8 too. Too bad I did not have it when I did my jeep 360 back then . Lucked out cranking it . I did make sure the oil pump cavity was as full of oil as I could get it , if that makes a difference . Less air bound , I guess . Well best of luck and I know you'll get it . Looking forward to good news soonest . Happy Thanksgiving All !

 

[flatie46]

Got it primed! The big hoss 'lectric DeWalt drill did the trick. I also noticed my distributor drive gear a bit loose. Under closer examination it was just about to shear the roll pin that held it on. It's up and running again, thanks for the input guys.

 

[greg92jeepxj]

Great to hear ! Was rooting for ya ! Yeah I knew you'd get 'er done ! Hey , was meant to be , pulling out the distributor , you found a potential hazard waiting to let go ! Real glad you found it ! Really glad you did , definately saved yourself trouble ! You the man !

 

[jps4jeep]

Good catch on the dist. gear, that would have sucked after the fact.

 

[flatie46]

Yea prob wouldn't have let go in the driveway, it woulda sheared in traffic halfway home from work.

One other thing that sucks is the oil pump is dripping, it's no biggie to fix but I hate re-doing it. Oh well...nature of the beast...mine anyway.