Do you need to prime or bleed a new oil pump?

[720inOlyWa]

I was wondering.... I cant find definitive info in my shop manual. It mentions filling it, but surely you don’t try to bolt it up full of oil... Do you just go ahead and replace the oil, then use that herkin plug to bleed it before starting again?

[datsunfreak]

You do need to prime it. For sure. 

 

Old school dudes say pack them full of vaseline. That works. 

 

Filling them with oil before install seems to work well too. 

[datsunfreak]

This works too:

 

http://community.ratsun.net/topic/25126-how-to-prime-oil-pump-on-a-new-l-motor-before-first-start-up/

[wayno]

I filled my LZ23 with oil before first start up and it did just fine, still running great to this day.

[INDY510]

What about a motor that's been sitting for 4 years, but the oil pump was never removed? ... Can I just fill the oil pan, and crank it without a coil wire?

[datsunfreak]

motor that's been sitting for 4 years, but the oil pump was never removed? ... Can I just fill the oil pan, and crank it without a coil wire?

 

FWIW, this is what I've always done. Never needed to prime it unless the pump was new (or was drained). 

[datzenmike]

If a new start up then just pour a cup of oil in the pump until full. Pull plugs and take the coil wire off and crank for 30 seconds. Engine should spin pretty fast this way and prime easily. If the valve cover is off you should see oil oozing from the cam.

 

If sat for years, pump should still have it's prime, pour oil liberally over cam and crank it.

[720inOlyWa]

Thanks, Mike. 

NAPZ, 2.4, as you must know by now. Having never done this before, I had a real hard time juggling the oil pump full of oil, the gasket and the mounting bolts without having the shaft fall down, etc.. When I put it on before, I struggled so much that I don’t think it had much oil in it by the time I got it all back together. It was one drippy mess, and clearly I did it all wrong. So now I find that I am a tooth off still, after checking over everything, and I have to pull the oil pump and distributor to get it right. THIS time, I will pull the distributor first and see if I cant rig up an elastic restraint so that I can carefully pull and rotate the shaft from underneath, knowing it will stay up in the gear when I let go. That is the plan, anyway. Taking one element of the juggling out of the equation should make replacing the oil pump that much easier. Does this sound reasonable to you all?

 

By the way, I horse traded for a couple of oil pumps along the way, so I am replacing the existing one with a new one. I have no idea whether it needs a new oil pump or not, but when I cold start, you can hear things rattling around in there a little for about 1 second before the oil arrives and it all gets quiet. This could be the trait of a dying oil pump, an oil pump that lost its prime on installation, or it could be perfectly normal for Z24 operation. I don’t know. In any case, since it is coming off to reset the shaft, a NOS oil pump replacement is going on.

 

Thanks for all the help. Most of this is new to me.

[Stoffregen Motorsports]

I'm a little late to the party here.

 

I usually stuff some assembly lube in the pump to help the suction side. If it's a new motor or if has sat for a long time, I pull the valve cover and douse the valvetrain with oil too.

 

If the motor will fire, I don't waste the time pulling the plugs and cranking it to build pressure, I just fire it off and watch the oil psi gauge or warning light. Firing a motor can get oil going a lot faster than cranking it with the plugs out. Watch the gauge or light and be ready to kill the motor if it's taking to long to build pressure. 5 seconds is too long in my book.

[ppeters914]

I'm installing a new oil pump in my rebuilt R16, and liking the assembly lube idea.

 

As for priming the rest of the motor, I'm a fan of the classic drill and screwdriver bit method.

[Stoffregen Motorsports]

In a motor with hydraulic lifters, priming the system may help a lot, but in a new engine that has assembly lube and oil all over everything, you really don't need to prime it with a drill.