no oil pressure, still....

Much time has gone by since I've started this project. I had the crank machined, installed new bearings (crank and rod), and rebuilt the oil pump.

I set up the timing, connected and adjusted everything, connected the gas, turned on the key, and it started right up. It was a great sound. But, the joy was short lived. I looked at the oil pressure gauge, and there was no pressure. I shut down the engine. I stared to think that there was no oil in the oil passages or the oil filter, so it would just take a minute to build up pressure. (yes, I added oil into the engine).

I stated it again, and let it run for a minute. Still no oil pressure. I disconnected the oil pressure line from the side of the engine, and started it up again. Oil did come out. But, it only trickled out. I connected the line back up, and disconnected it from the the back of the gauge, and started it again. It ran smoothly, but still no oil coming out of the oil pressure line.

The only thing I can think of is a bad oil pressure relief valve. But, I have it turned all of the wall in. I think it would take a lot of pressure to have it operate.

Can you guys think of anything else that I should look for? Your help is appreciated.

Roger

What tractor model?

Take a small wire and see if you can dislodge crud from the oil port in the side of the block. I think that the oil gallery may have some crud blocking the outlet.

The other possibility is that the oil pick up tube is leaking or cracked and not priming the pump.

1952 TEA-20

I could try that. When I had it all apart, I blew back the openings with air. I even checked all of the oil passages.

I'm going to drop the oil filter and crank it over and see how much oil is pumping out. If it doesn't look good there, then I drop the pan and check to see if the oil pickup tube is drawing air.

When I had it apart, the pickup tube and where it enters the pump looked like it would be submerged in the oil.

you said that you had the crank and rods done.did thay match the new bearring up with the rods and crank.did you plasti gauge the clearance on the rods and crank.and see that it is in spec range.

Pack the pump with white grease so it does not cavitate during initial start up is a good beginning. My TO has a pipe that connects the pump to the pick up tube. This pipe has rubber fittings in either end. The rubber ends could be sucking air, if yours is so equipped. These seals are available from your local hydraulic repair shop for a very minimal cost.
Blow gun on the oil pick up and soapy water to find the leak...

If the pick-up pipe on the oil pump is loose, it needs to be brazed into position. The pipe itself should be horizontal to enter the strainer in the oil pan. No need to drop the filter etc. just remove the oil gauge pipe at the block and check there or even on of the other plugs in the gallery. If it is just loss of oil pressure up to valve gear, it is possible that the head gasket is fitted incorrectly. You can check oil pressure up to Head by removing the plug on the back of the Head on the top left side, you should get a flow from there. Oil Pumps don't give much trouble, even the relief valve. If the clearances were wrong in the Pump, you would get a pressure to start with and then it would gradually tail away as the engine heats up.Have you checked the relief valve in the Oil Filter, if that sticks open you could possibly loose oil pressure, though it is unusual.Or is the adjustment backed off too much so it wont build up pressure. Are you sure the Pump is being driven, has the drive slotted together properly. Has the pin sheared on the gear driven from the Camshaft this engages with the Pump drive....John

Lots of good info.

I put in a new rotor. When I put in the drive gear for the distributor, it made a positive connection to the oil pump rotor.

I don't think the head gasket it misplaced, but anything is possible.

I will pull the relief valve out and inspect. While it's out, I'll turn over then engine and see how much oil is being pumped out.

dropped the oil filter and left the canister off. I turned over the engine, and oil came out. I started the engine, and the volume of oil being pumped out greatly increased. The pump is working fine.

I disconnected the oil pressure line from the side of the block, and stated the engine, some oil came out, but no where near the volume from when the filter was off. I removed a plug from the oil passage between the oil filter and where the pressure gauge was tapped off, and the same amount of oil would come out of there as from the oil pressure tap point.

I put things back together, and removed the plug from the back of the head and started the engine. No oil came out.

Is it possible the oil passage between the oil filter and the oil pressure tap point is partially plugged? Maybe. I'll check that out.

Not sure what else to check.

The wrong filter adapter is on the tractor. When I pulled the adapter off (the piece that holds the filter and bolts to the block), I started the engine. A LOT of oil came out of the hole. But, when the unit is on, only very little comes out of the hole in the oil passage opening that is only a inch away.

A close look of where the passages on the adapter line up with the holes on the block reveals that they don't line up. Oil goes into the filter, but, the return on the adapter doesn't line up with the hole on the block. It would appear that the relief valve in the filter chamber is opening up and alllowing some oil to go through to the oil passage and the sump.

I've confirmed this with looking at a neighbours tractor. Now, I have to try and track down a replacement.