Oil pressure "not"

Hammerun · Post by **Hammerun** » Sat Jun 21, 2014 10:38 pm

Just tonight I got the electrical worked out, as soon as the gas hit the carburetor, it was purring like a kitten. BUT, I thought to check and see if there was correct oil pressure. Zero. This was a total rebuild, 134F. What could be the possibilities? Does the pump have to be pre-primed? The one possibility I'm thinking is the pin that connects the pump gear to the shaft is missing.
I got tired and and had to give up for the night, now it's driving me nuts.
Any ideas?

Post by **wesk** » Sat Jun 21, 2014 11:14 pm

The very 1st thing you do! The very 1st thing you do!!!

Make sure the gauge works. The military electric sender or gauge or harness may have an issue. I always prefer to start a fresh jeep engine on old fashion mechanical type (direct reading) gauges for oil pressure and water temp. Just hook a direct reading gauge to the same port that the military sender is on.

Once we know we have a working gauge then check the engine for oil flow.

Leave the main ignition switch off. Open both of the oil gallery plugs on the left side of the engine and crank it over. Do you get oil flow from either plug? If yes then re-install those two plugs and remove the gauge or oil pressure sender from the rear end of the oil gallery. Crank her over and do you get oil flow from that port? If yes but still no pressure on the gauge then the problem lies inside the oil pan or inside the timing cover.

If the two plugs you removed 1st above did not flow any oil then remove the oil pump and fill it with oil and re-install it. If still no flow from the center two gallery plugs it's time to confirm that the two right gallery plugs inside the pan are installed and the cam gear spray nozzle inside the timing cover are installed.

Hammerun · Post by **Hammerun** » Sat Jun 21, 2014 11:27 pm

I did loosen the two gallery plugs on the lower,left side and got nothing. I'll take out the pump tomorrow and fill it and see what happens.
As usual, thanks Wes.

Hammerun · Post by **Hammerun** » Sun Jun 22, 2014 5:35 pm

Looks like I have to pull the motor. I'm suspecting a blockage in the oil galleries. The best scenario is when I get the pan off the oil pickup is loose or on the bottom of the pan. This thing is not pulling oil.

Post by **wesk** » Sun Jun 22, 2014 9:36 pm

I would try pressurizing the system with an external pump or pressure pot and engine oil. Unless you feel you missed something in your overhaul or assembly.

Hammerun · Post by **Hammerun** » Mon Jun 23, 2014 1:34 am

Where would you start, at inlet line into the filter canister down thru the fitting behind the fuel pump? And taking the fittings out at the rear of the block, hoping to blow the blockage out? Or hope to blow it out where the oil pump is? I'm not sure of the path the oil galleries. I think they run horizontal on the left side with the cam. What is their diameter? It looks like 3/8".
How about this. Remove the oil pump, there's two 1/2" holes either side of the pump shaft, take an air chuck with a rubber fitted end and open both ends and blow down both hoping to expel blockage.
I don't know, I'm about game for anything. I don't know anything about this pump, I haven't ran it in anything. For that matter this block is new as well. New to me that is, I didn't have it cooked out before I rebuilt it. I bought it from another party.

RICKG · Post by **RICKG** » Mon Jun 23, 2014 7:12 am

An inexpensive and effective pre-oil setup is detailed here..
http://willysmjeeps.com/v2/modules.php? ... ight=prime
Go to the end of the post for pics.

Post by **wesk** » Mon Jun 23, 2014 8:09 am

The external pre-oil suggestion was made to make your situation easier. It is something you should try before removing any major parts. You only need to remove a single gallery plug left or right of the oil pump and connect the pressure oil source there. The oil under pressure will flow through the system and exit at the bearings and the oil filter, several oil squirt holes and the front cam gear spray nozzle.

While doing this monitor your pressure indicating unit on the jeep. If you are relying on the electric gauge turn the master switch on.

If you now register pressure then disconnect the pre-oiler system, install the plug and start the engine. Oil pressure ok great. No oil pressure then pull the pump.

Hammerun · Post by **Hammerun** » Mon Jun 23, 2014 9:19 am

Ok, I've got the basic idea now. It might take a couple of days but I'll let you know how it came out, "or not". Thanks guys..

Post by **wesk** » Mon Jun 23, 2014 9:35 am

Hammerun · Post by **Hammerun** » Mon Jun 23, 2014 2:09 pm

Holy crap Wes, I just spotted something in that picture. The three 5/16ths bolts two are about 2.25" and the other about 1.25"long. The short one going into the flanged area into the block. All of mine the flange is on the bottom. I checked the other a1 ans an L motor I have sitting here. The pic shows the flange is up. Is it me or the pic?

Hammerun · Post by **Hammerun** » Mon Jun 23, 2014 2:18 pm

Looking at the post I might be unclear. The three bolts going thru the oil pump into the block.the flange on the oil pump.
BTW, I opened everything up and put 175 lbs of air thru everything. Nothing but oil came out. .I'm waiting for a set of gaskets for the oil pump and have packed it out with Vaseline. We're going to find out what's going on here.

Post by **wesk** » Mon Jun 23, 2014 6:54 pm

I suppose it would depend on your pump. Port alignment is the important issue. There are several style pump bodies and I would concentrate on aligning the oil ports in the pump with the ports on the block irregardless of pump body style.

This one is fat side up

This one has a very different shape.

Hammerun · Post by **Hammerun** » Mon Jun 23, 2014 7:38 pm

According to some minor measurements, on mine, the ports would line up with the fat side up and flange down.
In my quest via the local auto parts stores looking for oil pump gaskets, they seem to be NON EXISTENT! I've been looking at websites seeking them and ended up at Willys Jeep Parts out of Yuma Az. WALLA, got em!!
The part# 646147-E for a 134F engine. I noticed this one pictured looked a little different. So I went out in the shop and got the old one. I compared what I had in my hand to the picture. The one for the F head (pictured) had 7 holes in it, the one I had in my hand had only 6, which by the way matched the part# 630394, the one for the L motor. I noticed today that there was a 3/8 hole in the bottom that was being covered up by this gasket. Could this be the problem? It was wet, I don't know where it went. I poked a bore scope up at it but didn't see anything.
A machined hole covered up by a gasket seems to denote a problem, I think.

Post by **wesk** » Mon Jun 23, 2014 10:50 pm

Perhaps it was the suction hole to the sump!

Note that a lot more can be conveyed to your co-members with photos than words!