low oil pressure

ben harpo

Member
The owners manual is very clear that oil pressure should be about 30 psi on a Ferguson 30.

Mine was starting reading 30 psi at start-up but dropping to about 20 psi when fully warmed up.

I changed the oil and filter and used 15W40 oil, because that's what I had. I figured it would have higher pressure when hot, but I was wrong. Now it reads 40 psi at start-up and drops to almost 15 psi when fully warmed up. I'm not noticing any other problems except the reading on the gauge.

So what sort of problem do I have? And what is going to fail first if I keep running it like this?
 
Changing the oil to shell rotella 15w40 increased the oil psi in my tractor.

1957 TO35 still has the original oil pressure gauge so it does not have numbers but the 15w40 did keep the needle in the center.

Others may kick in here, but that oil pressure level may be ok, you have to remember these old boys are not new tractors.

Might get a oil filter from the local Ferguson dealer if you are using a cheap after market filter.

Also might add 1 qt. Of Lucas oil stabilizer, this is great oil.
 
A super hot engine from a stopped up radiator will effect oil pressure but most oil drops are either a stuck prv, bad pump, or bearings.Would I worry? Yes!! Would anybody else? No, 20 isa plenty.
 
I've ran my TO-20 for two years putting several hundred hours a year on it, plowing,raking hay,discing,cultivating,etc...and it only has around 20 pounds when hot.90% of my farm work is done with that tractor and I have had no problems. The rule of thumb is 10 psi per 1000 rpms.
 
Joe

"Even in Summer when hot the guage shows 75-80 psi."

That is waaaay too high for a Standard engine. You can't have both oil pressure and oil volume.

Should be around 60 PSI cold, 30 to 40 PSI warm.

Ben

Engine getting tired, oil pump worn or oil pressure relief valve needs adjustment? May pay to adjust the relief valve or replace the oil pump. Treated with care that oil pressure is low, but not too low.

Bob in Oz
 
I used an aftermarket c3p oil filter which was smaller diameter than the MF filter that was on there. Don't see how that would make much difference.

The manual shows the oil pump as on the bottom of the engine. Is it easy to get to by removing the oil pan on bottom next time I go to change the oil? Or do I have to take most of the engine apart?

I don't know anything about how to adjust the pressure relief valve. Tips?
 
I would like to have more than the 5ibs my tractor puts up when cold! but then it has been working since 1985 with this amount of oil pressure and seems to have got used to it! I do keep the oil and filter fresh and check at the tappets for oil flow.....If the oil is reaching the tappets at an acceptable rate then everything else is getting lube on the way up there. Modern cars put out the idiot light for oil pressure at about 6lbs pressure!
Take Tony's advice and paint over your gauge!
Sam
 
The pressure relief valve inside the oil pump requires pulling the pan, removing the pump.Jerry and others schooled me on its operation while I rebuilt a to20. Type relief valve in the search column to find the info in the archives.If the spring is weak I suppose 30psi may collapse it and expose the relief bypass hole and require a shim or a new spring. While you have the pan off I would advise that you first plastiquage the bearings to see if that is the problem but with 20 lbs its best to LEAVE IT ALONE.
 
I had a similar situation in my TO30. About 20 psi when fully hot and at working RPM, about 5-7 psi when really hot and idling.

After checking my oil pump I determined it was fairly worn. I put in a new one. My oil pressure jumped only about 5 - 7 psi when really hot--both at idle and working RPM. (Not sure what others advise, but when fully hot I make sure I don't go below a slightly fast idle to get at least 15 psi. Only a tiny bit more engine speed makes the difference.)

After plastigauging the main bearings, I think I would need to replace them to get the pressure up where it "should" be. Maybe someday. They are still within the range my manual permits, although near upper limit.

Replacing the pump is relatively straightforward, but in my case it was only part of the issue. Of course, every situation may be different.

As most are saying, keep good oil in it and you can probably run it as is until when/if it gets worse.
 

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