Jump to content

Oil Pump Priming


Sask466

Recommended Posts

A little background.  I have an '86 IH s1900 chassis with a DT466.  I have it stripped to the frame, and I will be putting a '65 F700 cab onto it.  I  had the pan off while I fixed up a leak, then I buttoned it back up but never put oil back in it for a few months.  So, if sat without  oil for a few months.   

I also replaced the turbo with an S2E during this period.  Prior to start-up, I was weary of running the turbo dry.  So, I put oil into the pan and didn't get back to the job for a week.  About a week later, I no-fuel cranked the engine over for about 20 seconds - no oil out of the turbo feed line.  Not a drop on the oil first filter either.    

 

So, I figured I would loosen the first filter in an attempt to lower any possible head on the oil pump.  Another 15 seconds, still nothing, not a drop.

 

Next step, take a garden sprayer and push a gallon into the oil pressure sender port.  Got to have it now right?  Nope, no oil out of the turbo feed line after 15sec.

 

Next step, what about they 1/4" bung on the oil cooler, the pressurized oil fed through the pressure sender port should squirt out of the bung like crazy?  Nope, not a drop.

 

In light of that, I then figured what the heck, might as well push another gallon through the oil cooler bung.  The oil seemed to push though easier and hardly even got to the turbo feed tube - like most of the oil was flowing backwards through the oil pump.  Also heard some air bubbling in what I imagine was the oil pan area. 

Tried the starter again, and the pump started pushing oil out the turbo line like a faucet.  

 

You never know what is coincidence and what is fact, but it seems like there is a check valve between the oil sender/filter area and the oil pump.  But who knows, could have been bad luck/dumb luck.  Anyone have an oil system diagram?  I can't find one.

 

Does anyone have similar experiences from after a motor sitting for an extended period, or a rebuild?  This seems a bit strange to me.  One might wonder if the oil pump is getting weak, but it makes really good oil pressure and has been really quick to build pressure prior to that.  It seems like the pump got dry from sitting a few months, and just couldn't get a prime until it got wetted with oil.

 

Maybe it would have sucked the oil up had I just fired the engine up, as cranking rpm is pretty low.  But with a new turbo, I wasn't going to take that chance. Truthfully, I probably wouldn't have worried about verifying oil pressure prior to starting, had it not been for worrying about the new turbo.

 

Also, to throw in a possible red herring the oil is 15w40 Rotella!  Sorry, thats in jest.  I wanted to use 30wt, but it is getting to be hen's teeth up here with our cold climate.

Link to comment
Share on other sites

Had a 1066 once that I Inframed that I had to prime oil in sender hole wouldn't pick up oil after it ran for a second.  Also on on a v6 I think they were the first 3.8 in fm cars. They ran external oil pumps. You had to pack them with grease and oil when installing so they would prime.

Link to comment
Share on other sites

I always put white grease or something on gears to create a suction. Also use an oil primer on left side of engine, cam side.

Link to comment
Share on other sites

On 9/4/2016 at 10:37 PM, dale560 said:

Had a 1066 once that I Inframed that I had to prime oil in sender hole wouldn't pick up oil after it ran for a second.  Also on on a v6 I think they were the first 3.8 in fm cars. They ran external oil pumps. You had to pack them with grease and oil when installing so they would prime.

So how do they reprime after an oil change or having sat for a long time?    

To me any oil pump that does not self prime is junk. 

Link to comment
Share on other sites

Brian, how come you prime on the cam side?  Is it to get oil on the cam side to make sure you get the tappets oiled?  My issue was with getting the pump sufficiently wet to start making suction to prime.  I thought the cam side was on the back end of the oil flow, so would oil get to the pump this way? 

I bet the pump would have likely primed if I had just fired up the engine (it has in the past), but it probably never would have at cranking rpm's...

Maybe my pump is getting tired, who knows.

Link to comment
Share on other sites

I prime on cam side to get the cam oiled, and i leave oil line off to pump, so i can see when oil comes out. then i hook line up and continue so pump has oil. its just the way I've always done it, right or wrong. injection pump i should say. i start engine right away and get the rpm's up to 1000. If the pump is dry its hard to get to prime, thats why i always use a white grease or something, to get the suction going.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...