New engine overhaul, no oil pressure

[meandmydeere]

Just did a major on the engine and I was trying to get it started the other night, I have no oil pressure. I primed the pump but maybe I didn't shoot enough oil in. Maybe I should use 90w. How much oil should prime the pump?
When purchased, the engine was in a box. The block was bare. The key is in the cam, the oil holes in the bearings are lined up with the block oil holes.
What have I missed?
Mark

[Bigdog]

Remove the oil filter housing cap and pull the filter. If you look inside you will see a small hole. Shoot that full of oil with a pump oiler and crank it over. There is also a set screw above the oil pump in the rear flange of the block which can be removed for priming. Look by the hydraulic pump lines to the touch control unit.

[meandmydeere]

The allen screw under the hydraulic lines is where I primed the pump at. I also poured oil right in the filter housing. However, I did leave the filter in place so maybe enough oil didn't get down the hole.
Mark

[Eugene]

As a guess, about 1/4 cup of oil to prime the oil pump. Squirt the oil in, let set for a while for the air bubbles to rise, more oil.

Oil poured in the oil filter housing drained into the crankcase.

Use BigDog's suggestion. You may have to put a finger over the hole in the oil filter housing to keep oil in the gallery.

Pull the spark plugs, add a bit of oil to each cylinder then crank the engine over with the starter. Have the top removed from the oil filter housing. You can then see when the oil starts being pumped.

Wiring diagram for the lubrication system - look under PVR Pressure Wow - down about 10 positings.

Hope this works.

Eugene

[meandmydeere]

After some serious head scratching, I am still stumped. I have minimal oil pressure now. It takes forever to fill the filter housing and then I get a teeny tiny bit of movement on the oil pressure needle. The prv is free but the spring doesn't put any tension on the hex cap. Should the spring be a little longer? I read in the service manual the length it should be so I will check the length and try again tomorrow.
Mark

[John *.?-!.* cub owner]

before you go to deep, get another gauge (about 10 or 12 dollars at most auto parts stores for a universal and try that.

[awander]

$8 for a water pressure gauge a t Home Depot-look right by the pump stuff.

[Jim Becker]

I hate to be the one to bring this up, but there is another oil gallery plug. It is on the front of the block, behind the timing gear. If it was removed and not put back, your oil could all be dumping back into the pan from that opening. I'm not sure how to even verify it is in place without doing a LOT of work.

[John *.?-!.* cub owner]

I believe I remebe someone confirmed this problem by putting air presure in the priming hole and listening with a stethoscope at the fornt of the engine..

[Eugene]

One more thing to check out. See if the oil pressure regulator valve is fully closing. Something may be holding the valve open.

Try the air pressure check as John suggested.

Key is in the cam - do you mean the key in oil pump drive gear?

Eugene

[meandmydeere]

When I said the key was in the cam, I was trying to let everyone know in a nice way that I have built several motors and I know the basics.
I think Jim may have touched on the problem. All the allen head screws were removed and I may have missed the one behind the timing gear. When I bought the tractor, all the parts were in boxes and all the bolts were in bags. There are no allen screws left over but that only means I put most of them back.
I will tear the frontend back off today and check for the missing oil galley plug.
Mark

[George Willer]

The air/sound suggestion was mine, but I don't recall who the unfortunate guy was. That plug requires a MAJOR tear-down to replace and it WAS his problem.

Another idea of something that can be more easily corrected and that can happen even to an experienced mechanic is standard bearings used with a ground crank.

That happened on an A-65 Continental aircraft engine I had majored years ago. On first run-up the pressure was very low and the (very experienced) A&E mechanic thought it was the oil pump. I insisted on a tear-down to check the bearings. Yep! Wrong ones.

[meandmydeere]

George: The bearings in the tractor were standard. Stamped 9-52. However, when I got the new bearings from our local IH dealer, the thrust bearing was .10 under. They said the computer doesn't offer a standard thrust bearing. They do and I got it. So to others out there, make sure that all the bearings are the same. Apparently this is an error in their computer.
I am going to do some checking today but I think the allen screw behind the timing gear is the culprit. That makes the most sense since it is the hardest to remedy. No big deal. I am a John Deere collector therefore a perfectionist.
Of course it could be the gage because I have a John Deere gage on it right now. LOL
Thanks for the help, Mark

[Kodiak]

I had the very same problem about a year ago with my cub when the engine was rebuilt. The allen screw was the culprit. Got it back in place and wham all kinds of oil pressure! It sure was a lot of trouble to fix but that's the way it goes
Runs great now

Ron

[(CUB HUT)]

meandmyjohn
" That makes the most sense since it is the hardest to remedy. No big deal. I am a John Deere collector therefore a perfectionist"

Be Careful and not get any RED PAINT under your finger nails!!!