Oil pump won't prime......

[RECHRGD]

Got the new HV pump yesterday afternoon.  Took it apart and all looked good.  Squirted a little oil in it and the installation went without issue.  Went out today to prime it and it wouldn't prime.  I ran the priming tool CCC for up to three minutes a few times, varying the speed, but not fast.  I've never had a problem doing this before and just don't get it.  I filled the filter with oil before installing it. I don't really want to have to take it off and do the Vaseline trick that people talk about.

[Challenger340]

Did you fill the Filter right FULL ?   

Sometimes it takes a while to fill the filter(5-7 Minutes), let it sit and settle through the paper,, then refill, and again, and again, until it won't take anymore, THEN install and prime counterclockwise.

Just "filling" it once then installing it won't work, because, once that initial full volume settles through the paper it's only about 1/3 full and insufficient to immerse the oil pump rotor.

[RECHRGD]

Did you fill the Filter right FULL ?   

Sometimes it takes a while to fill the filter(5-7 Minutes), let it sit and settle through the paper,, then refill, and again, and again, until it won't take anymore, THEN install and prime counterclockwise.

Just "filling" it once then installing it won't work, because, once that initial full volume settles through the paper it's only about 1/3 full and insufficient to immerse the oil pump rotor.

Yes, I actually filled the filter four times.  But, as we all know, lost a substantial amount of oil while trying to get it threaded onto the pump...........

[ws23rt]

Something feels wrong here.

First is ---I have done this more than a few times and "5-7 Minutes" to fill the filter must be a miss statement. --Maybe 5-7 seconds??

The next question is. How do you know you have not achieved priming?

I recall doing this with a drill motor once and feeling resistance to begin with. Shortly after that it ran easy for a few seconds until I could feel a bit of torque again. To me that was priming.

If you can't see oil coming out somewhere on the engine (the lifter valley for example) or showing up on a gauge that would be the true test.

[BSB67]

I don't have an answer for you.  An oil pump is an incredably simple device that will essentially never wear out enough that it would matter.  And I have never heard of a factory unit having a problem.  That said, I've said for years that Melling pumps are junk.  Maybe now they are even worse.  Why wouldnt they, everything else seems to be.

When I read your first post on this, it did not, and does not add up for me.   Maybe packing it with vasoline will make your problem go away.  Hope so.

Save the old pump.  If its problem was really a sticking relief valve (kinda hard to believe if it's been in the motor for awhile) then fixing that problem takes about three minutes.

Finally, if you continue to struggle with priming the motor, it could be a cracked pick-up.  It would sort of explaing both your past and current problems.  Just spit balling here, but keep it in the back of your mind if this problem persists.

[cdr]

dont get mad,,,,,,, is it full of oil?

[RECHRGD]

OK, took the damn thing off, jammed it full of patrolium jelly and it primed in about five seconds.  Tomorrow I'll throw the distributor back on and see what I have for pressure...... Pray for me........

[RECHRGD]

dont get mad,,,,,,, is it full of oil?

No sweat Charlie...  I'm perfectly capable of something like that at this age........

[cdr]

dont get mad,,,,,,, is it full of oil?

No sweat Charlie...  I'm perfectly capable of something like that at this age........

So am I, HAHA, Thats why I asked, LMBO

[Chargerguy74]

Something feels wrong here.

First is ---I have done this more than a few times and "5-7 Minutes" to fill the filter must be a miss statement. --Maybe 5-7 seconds??

The next question is. How do you know you have not achieved priming?

I recall doing this with a drill motor once and feeling resistance to begin with. Shortly after that it ran easy for a few seconds until I could feel a bit of torque again. To me that was priming.

If you can't see oil coming out somewhere on the engine (the lifter valley for example) or showing up on a gauge that would be the true test.

It's definitely a few minutes to fill a filter.

[redgum78]

Finally, if you continue to struggle with priming the motor, it could be a cracked pick-up.  It would sort of explaing both your past and current problems.  Just spit balling here, but keep it in the back of your mind if this problem persists.

Does sound like it could be pulling air from somewhere.

[myk]

OK, took the damn thing off, jammed it full of patrolium jelly and it primed in about five seconds.  Tomorrow I'll throw the distributor back on and see what I have for pressure...... Pray for me........

What petroleum jelly do?  Anyway, fingers crossed bud...

[68CoronetRT]

OK, took the damn thing off, jammed it full of patrolium jelly and it primed in about five seconds.  Tomorrow I'll throw the distributor back on and see what I have for pressure...... Pray for me........

What petroleum jelly do?  Anyway, fingers crossed bud...

It gives the pump a chance to prime. Currently it's just spinning and moving air(cavitating), once oil or something takes the air's place then it starts pumping fluid. Hope that makes sense.

[Challenger340]

Something feels wrong here.

First is ---I have done this more than a few times and "5-7 Minutes" to fill the filter must be a miss statement. --Maybe 5-7 seconds??

That is EXACTLY what I am talking about here ? It is NOT a miss-statement.

As a test...
The next time you FILL your Oil Filter in the 5-7 "seconds" ? ..... WALK AWAY for about a minute.... then come back and see how "Full" it is ?
Then re-FILL again...
repeat...
as req'd....
until you can come back and it is indeed stays FULL.

[RECHRGD]

OK, I'm a happy camper!  Got my pressure back and valve train noise is way down.  Sounds like I may have a rocker that needs adjusting though.....

[firefighter3931]

Been following this one but had nothing further to add as the advice has been spot on. 

Good to hear it worked out well for you Bob. 

Still curious as to why the pressure dropped off ; was it wear on the pump rotors or possible bypass valve sticking or weak relief spring ?   

Maybe when you have some free time it might be worth a quick look see inside the pump ? 

At any rate it's fixed so you're back on the road 



Ron

[RECHRGD]

Been following this one but had nothing further to add as the advice has been spot on. 

Good to hear it worked out well for you Bob. 

Still curious as to why the pressure dropped off ; was it wear on the pump rotors or possible bypass valve sticking or weak relief spring ?   

Maybe when you have some free time it might be worth a quick look see inside the pump ? 

At any rate it's fixed so you're back on the road 



Ron

Hi Ron!  I have opened them up, but really don't know what I'm looking for.  Being that I regained decent pressure when I replaced the original H V unit with the standard one, I just assumed that the bypass valve had stuck partially open.  Now when the new one dropped pressure and wouldn't regain it, I was/am at a loss.  I may be over thinking things, but this happened right after I did a little punch off with a new Challenger and let off at about 110/115 (btw the old girl did herself proud).  My thought is that at the higher rpm the bypass opened but would not close completely after returning to lower rpm.  With the new HV pump my idle pressure went to 59lbs..  Today I went for a little drive and after a full warm up it dropped to around 55lbs..  I didn't notice any increase in pressure above idle, but at the same time, did no highway driving.  The no increase in pressure above idle has me somewhat concerned, as the short block is approaching 50K miles.  At the same time though, the high pressure at idle would indicate (to me) that the engine is still pretty tight.  I haven't been able to determine what the pressure needs to be in the Melling HV pump to open the bypass.  Do you know?