No oil pressure

I have little or no oil pressure on my farmall C. Seems to run o.k., no smoke.
What should I look at first? It may need main bearings, but I hope something simplier.

Please advise.
dww

check the oil pump. i have seen a few where the bottom plate warps and loses the oil pressure

Oil pump. Plate in bottom has to have proper clearance.

Couldn't hurt to check out the gauge, either.

Is this a new development?

Could be as simple as real low on oil.

I wouldn't run it until you find out what's going on or you'll be looking at some money.

Pressure is built or lost betweent the face of the gears and the plate. Volume is made or lost through the amount of backlash in the gears. You can hand lap the plate back perfect flat on a precision surface plate, but I would put another guage on it and make sure it's not a guage problem if it started all of a sudden like. After that, bearings/journals are next.

scott#2

You may have sludge over the pickup screen on your pump or could be the pump as others have suggested. Hal

dww, hope I'm not talking out my *ss, but I think it's the same engine as my Super-A.
My gauge reads to 30#, (not sure if it was the original gauge), but it was only reading 10# in use. I overhauled my engine, (incl. bearings) as well as my oil pump, so I don't know for sure where I fixed the problem, but now when in use, the gauge stays pegged at 30#, and may want to go higher.

As the oil pump is the easiest to look at, I'd start there first. The intake sump is [u:364913476a]hinged[/u:364913476a], so that it will float on top of the oil in the pan. This way, it doesn't get down into the sludge on the bottom, but also so it will follow an oil level that is dropping. If this hinged-action isn't free, your sump may be riding above the top of the oil.
Secondly, there is a screen on it, and it may be getting clogged.

The whole oil pump is very easily removed for inspection, once the oil pan is dropped. Only need to remove two bolts on the side- seen here just above the pan, below the oil filter pedestal.



The pump in it's entirety can then be removed. The shaft of it goes through a drilling in the block, and it's gear engages with a gear on the camshaft, and you can see the drilling and the cam-oil-gear above the crank toward the left side of the pic. the pump/shaft may just drop out, or like mine, may need to be twisted and pulled to extract it.



The "plate" that has been mentioned covers the bottom of the pump, and here has been removed.



I discovered that 1/4" of the paper gasket had been blown out, which certainly didn't help hold up the pressure.
Here's a pic of my bottom plate, and you can see how the gears cut into it, which also affects the pressure. I had a machinist mill mine flat.



It calls for a certain amount of clearance when reinstalling. I happened to get two of the paper gaskets with my 'engine rebuild' kit. With only one gasket, the gears would bind, and with two, they turned freely, so for me, there was no measuring that seemed necessary, and I buttoned it up with both gaskets, with happy results. Other folks may tell you different, about the checking.
So, my advice is to have 2 gaskets on standby. They are very delicate, and very thin, I believe .006 thick.

One last thing, you can easily check to see if the gauge is free- it would move easily with a shot of air from my air compressor.
One other thing to check is the spring on the oil pressure relief valve, to make sure it's not broken. If I understand right, if it's broken, your pressure will bypass the block and get returned right to your oil pan. That valve is also within the pump.
Keep us posted with what you find.

Thanks for all replys. I have something to work on now. Once I take a look at the oil pump, I'll get back to you. Hey, the pictures are a real help!
many thanks.