Farmall F-12 Oil Pressure

[wowsk]

When I start the F-12 the oil pressure is great. Over halfway up the gauge at low idle. After running the F-12 for 10-15 minutes and the oil heat up the pressure drops to right at the top of the red at idle and just above at fast idle. All the other Farmalls we have keep good oil pressure no matter what. I have completely cleaned the oil filter housing, put on new gaskets and made sure there is no leaks. Is the next step to replace the gasket on the oil pump?

Thanks for the help. Before I drop the pan again I want to make sure I'm going about it the right way since take the pan on and off is such a pain with it. Anything else I should check if I take it off?

Thanks,
Noah

 

[caterpillar guy]

After looking at the oil pump for gasket problems. I guess you could look at the bearings. Plastigage them for oil clearance if that is correct then do the same for mains. If all is good there then it is either a weak oil pump or loose cam bearings which would require a major amount of work to correct. If those are poured rods and not inserts it is more work to adjust them for clearance on them. I can not say whether they are or not.

 

[redforlife]

If I were a betting man, I'd put my money
down on worn engine bearings. Could be
wrong, but stands to reason that if you got
adequate pressure when cold, and not when
hot, that is what is going on.

An F-20 has babbitt rod bearings that are
dipper bearings, and ball bearing mains.
I'm presuming an F-12 has likewise. So if
it is engine bearings, it's likely cam
bearings.

High oil pressure is not crucial on an F-
12. It's more important that it has SOME
pressure, versus none.

I definately wouldn't be pushing the panic
button just because you think it's got
border line oil pressure.

 

[Michael Soldan]

Dump a can of STP into the crankcase. Oil pressure will come up.

 

[Glenn F.]

While I agree with you in theory I have never seen increased oil viscosity improve oil pressure after engine is brought up to operating temperature.

Glenn F.

 

[BarnyardEngineering]

My preferred choice is Lucas Oil Stabilizer. Put the whole quart in. Doesn't help much but it does help.

 

[rustred]

the engine brg. are worn. the pump cant keep pressure up when the clearances in brgs. get to worn. put your thumb over a running garden hose
you will pressure it up and water will be spraying every where. when thumb is off you have zero pressure. same deal in an engine. cold oil
will show more pressure till it heats up and looses it vicosity.

 

[wowsk]

Thanks for the advice. I'll try some oil stabilizer first I think I have some on hand. If that doesn't help I'll try the oil pump gasket and check the main bearings. I'll go from there.

Thanks again,
Noah

 

[Fritz Maurer]

The F12 is neither splash lubed nor has Babbitt rod
bearings. It is a full pressure system. Pull your filter
housing back off and make sure it is absolutely flat
and not allowing cross-leaks. Check to see if the oil
pressure regulator spring is not broken or incorrect,
and that the regulator piston is not stuck. If all is
well outside the block, all that is left is the pump
and/or the bearings.

 

[rustred]

i explained it too you. check you rods first for wear, if signs of wear then continue. the biggest cuplprit is the cam brgs. your making no
sense. stabilizer will help the viscosity some, buy is is not a fix! you have a worn out engine. so 2 options use you stabilizer or tear it
down for rebuild. an oil pump can only do so much on a worn engine.

 

[Pete in Holland MI]

What weight oil are you using? Suggest trying a change with 15w-40, or even try some 40 weight. If you just tinker around
with your 12, a full rebuild may not be in the cards or warranted. Heavier weight oils will help with oil pressure.