Oil pressure

Tom H. · May 26, 2017

Just put my #1 TO30 back together, had the inner thrust bearing decide to come apart. Minimal wear on the bearings themselves, but I have always had a low oil pressure issue with this motor. Rebuilt the pump again and still same problem. Above idle hold just over 10 psi and drops to near 0 at idle. Checked with my pressure test gauge and reads a little higher but that's it. I read in the archives that the pump itself may be worn and have found one on fleabay to rebuild and try. Just looking for any other direction to go besides this. Other pumps that I have rebuilt all hold good pressure. Thanks

Tony in Mass. · May 26, 2017

To me, there should be a 3 credit course in 'rear main bearings'. I've spent more time and brain power... ya ya, on them, than on pumps. But since i am certain you will do a good job on the new pump... so if that don't cure it.... besides blocked passages, there's nothing else to it!

Mike Groom · May 26, 2017

Bearing clearance generates oil pressure,I would check your cam bearings and main and rod bearings for clearance with plastigage before I would blame the oil pump.

maxwell99 · May 27, 2017

I took the easy way out with my old tractor,
It starts and runs good, but had low oil pressure when it was warm,

I just changed oil from 10w40 to shell rotella 15w40, old tractor seems to run fine on this oil and holds a higher oil pressure,

Tony in Mass. · May 27, 2017

10 is suppose to be for cold as it gets in the lower 48, but in northern Canada, they sell zero w 20.... i don't want to be where you need 10 weight, no one should be where an engine needs zreo weight just to turn over...
I use the Rotella 15-40 in everything, including the tractor trannies.

Steve@Advance · May 27, 2017

It could be the pump, could be bearing clearance, could be anything hat allows internal oil leakage.

If you feel good about all the bearing clearances, the pump would be the next suspect.

But instead of taking a chance on a used pump, why not go with a new one? The wear on a pump is more in the housing than on the gears, so rebuilding a used pump with new gears is not always beneficial.

I don't have a manual for the 30, but what kind of oil filter system does it have?

Is it a full flow system that filters the oil after it leaves the pump?

Or is it a bypass system, that filters a small amount of oil then dumps it back in the pan? If it is a bypass system, there will be a restrictor orifice to limit the flow. Be sure it is in there, otherwise it will flow too much oil.

Tom H. · May 27, 2017

Thanks everyone. I will see how the new, old pump looks before I pull the trigger on a new, new one

Jerry/MT · May 27, 2017

Check for a stuck open relief valve. If that"s not it, it"s bearing clearances too large, or worn oil pump or all of the above.

2tractors · May 28, 2017

I can think of only one thing worse than rebuilding a low pressure pump and not having any good results and that's rebuilding the front tranny seals with none.

Oil pressure

Tom H.

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Tony in Mass.

Well-known Member

Mike Groom

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maxwell99

Well-known Member

Tony in Mass.

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Steve@Advance

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Tom H.

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Jerry/MT

Well-known Member

2tractors

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