Cummins (or other) oil pump priming during assembly

[fitterski]

The book says to fill the oil pump with oil before installation ...or else. Ok, I get the message and it makes a lot of sense too.

The thing is that even if I do fill it the engine will be rotated every which way a hundred times before I ever get near that first start.

There's gotta be a better way, like pumping the pump full just before first start somehow.

 

[90cummins]

When I did major work on my 99 CTD I purchased an oil pump on eBay. I then removed the drive gear and ground 3 flats on the shaft so I could turn it with my 1/2 inch drill.
Worked slick.
90cummins

 

[CincyFlyer]

It is not unheard of to pull a gallery plug (or perhaps an oil pressure gauge) and plumb in some oil before starting an engine to get the system primed. On many V-8 engines you can simply spin the oil pump with an extension rod (it's driven by the distributor).

 

[fitterski]

Ok, the book: "Failure to fill the pump with oil during installation can result in a slow prime at intial engine start-up, resulting in severe engine damage". First I misread this thinking pump-damage and not engine-damage. The engine I'm not worried about, everything is pre oiled and I would expect to see pressure while cranking long before any real start attempt. But I think pressurised pre-lubrfication __IS__ the way to go. So, if I plug a pressurised source into a gallery outlet, will that fill the PUMP with reverse flow? I once saw a guy hang a gallon of oil high above the engine, didn't pay attention then, I figure he was doing the same thing with gravity feed just before a start.

Anyway the bit in the book makes no sense because oil in the pump will be long drained out before a start, or so I fear not to mentin the fact that I would have to stand the engine on its rear to fill the pump and be able to install it full of oil.

 

[pmsmechanic]

It is not unheard of to pull a gallery plug (or perhaps an oil pressure gauge) and plumb in some oil before starting an engine to get the system primed..

I did this once. Never again! It could be that I did something wrong but the oil system air locked and I had to relieve pressure before the oil pump would prime. I can see using gravity to prime the oil system but I was told to use air so I did.

Now I alway turn the oil pump to prime the oil system before starting. At the very minimum I would fill the oil pump with oil and turn it by hand a few times before installing it.

 

[Winmac]

Here is my take on it.
A completely dry oil pump may not be able to prime itself, filling with oil even after it drains off will leave an oil residue that will seal clearances within the pump. Helping it self prime instantly on initial startup.

 

[CincyFlyer]

I did this once. Never again! It could be that I did something wrong but the oil system air locked and I had to relieve pressure before the oil pump would prime. I can see using gravity to prime the oil system but I was told to use air so I did.

Now I alway turn the oil pump to prime the oil system before starting. At the very minimum I would fill the oil pump with oil and turn it by hand a few times before installing it.

I actual meant to introduce oil under pressure through the chosen port; no air is involved!

 

[DEWFPO]

Some folks pack the oil pumps with petroleum jelly to get rid of air and get a quick prime. The vaseline would melt into the oil pretty quickly and not cause a problem. It sure beat trying to build pressure in a sleeping engine, especially a diesel.

DEWFPO

 

[KWentling]

I resurrected a 4BT out of a generator that had set for about 5 years. I just disable the start solenoid and cranked it over until I had oil pressure.

 

[Snobdds]

Some folks pack the oil pumps with petroleum jelly to get rid of air and get a quick prime. The vaseline would melt into the oil pretty quickly and not cause a problem. It sure beat trying to build pressure in a sleeping engine, especially a diesel.

DEWFPO

This is what you should do. It's pretty common practice to put vasoline in the oil pump prior to assembly. Then you should have no worries.