440 Oil Pump Won't Prime

-
R

racingsnake440

Well-Known Member
Joined
Aug 29, 2005
Messages
337
Reaction score
37
This driving me nuts!
Swapping in a 440 motor home motor. Had to change the pan and pick up to car style ones, used a factory pan and factory style pickup which is right on the floor of the pan. Put new gaskets/seals in the pump while I was at it. I packed the pump with petroleum jelly to help it prime but got nothing on the oil pressure gauge when I spun it with the drill. Took the oil filter off and saw a small blob of the petroleum jelly pushed out of the housing and into the filter. Decided it was probably a mistake using the petroleum jelly so took a known working used oil pump I had, cleaned it up, new gaskets and seals and coated rotors and housing with oil. Put it on, still no oil pressure. Took the filter off and ran the pump with the drill again, there's a 'buzzing' noise coming from the outlet on the filter housing but no oil. I've used my cordless and corded drills running on high speed (counterclockwise), I ran the corded drill for 2 minutes and got nothing. The filter was half filled with oil when I put it on, the pan has 4.5 quarts and shows full on the dipstick. I’ve also cranked the motor with the plugs out, the oil light doesn’t go out and nothing registers on the mechanical oil pressure gauge.
Think it must be an issue with the pickup - anything I could be missing before I tear it down? The engine ran fine when it was pulled from the motor home
 
It's too thick for the pump to move. Clean the pump out and just let it suck the oil out of the pan on its own.
 
RustyRatRod said:
It's too thick for the pump to move. Clean the pump out and just let it suck the oil out of the pan on its own.
Click to expand...
Already done that - I swapped to a different known good pump that just had a coating of engine oil put on the rotors and housing.
 
When I rebuilt my 340 with new stock pump It took quite a while before I got pressure. I gave up 1st try and spun it for some time before the drill finally bogged down and got pressure.
 
Kendog 170 said:
When I rebuilt my 340 with new stock pump It took quite a while before I got pressure. I gave up 1st try and spun it for some time before the drill finally bogged down and got pressure.
Click to expand...
I’ve run the drill for at least 2 minutes multiple times, surely that’s enough?
 
Possible that the pan snapped the tube during installation? Idk. Gotta weird one.
 
Your suckin air somewhere check for a cracked pickup , pump not seated properly , **** like that . You got more problems than petroleum jelly .
 
Last edited:
RustyRatRod said:
It's too thick for the pump to move. Clean the pump out and just let it suck the oil out of the pan on its own.
Click to expand...
Agree. I've heard of the vaseline prime trick but never used it no need to. Install pump and prime with drill before firing. also verify which way the drill is spinning...I know its dumb but some engines the distributor spins the other way ask me how I know...I think BB Mopar is counterclockwise...:)
 
thesiren74 said:
Turn the engine while priming, had to do it on my 413 and took a while.
Click to expand...
That won’t do anything
He is going counterclockwise.

Try a different oil filter and put it on dry, just because it so to do.

Take the pressure relief valve and spring out and make sure it is clean and moving. Unscrew the plug on the back of the bore. But since you tried 2 different pumps with zero oil press then the pan may need to come off and check out the pickup.

I like to put some oil in a new oil pump just so it is wet. You don’t need to pack it full of grease or Vaseline, it doesn’t belong inside the engine anyway.
 
Last edited:
I've never used vaseline. Just threw a little oil down in the pump. PRIME FIRST WITH THE FILTER REMOVED!!! This relieves all head pressure on the pump. If it does not pump in about 3 seconds or less, there is something wrong.

As others, you may have an air leak. You sure you have the o ring on the pump stinger that enters the block?
 
72Duster440 said:
You said pickup is right against the pan, is it too tight to the pan not allowing any oil to pass?
Click to expand...
That's impossible the way the pickup is designed.....as long as he has the stock pickup. They are designed to touch the pan bottom.
 
If you're confident you didn't stress the pickup tube threads causing it to crack on the install, you might consider pulling that pump apart again and make sure the rotor isn't bound up.
 
Maybe an engagement issue? I remember last one I did would really bog a 3/8 drill, had to use a good 1/2" drill to get enough rpm.
 
on stubborn motors to prime it using a drill i've filled the motor until the level inside is higher than the pump. now gravity works in your favour priming the pump as well as it sucking. once primed drain the pan and refill to the correct level.
 
You must log in or register to reply here.
-

Back
Top