Oil Pressure Issue with TO 30

Hi

Back again for some much needed advice.

Oil pressure over the last several months has starting dropping from 3/4 on gauge to 1/4 over the course of several hours run time. Oil changed and crankcase is full.

Over the last two weeks the pressure has now dropped to near the red line. I have to run the engine's throttle high to maintain pressure in the white. Going down a hill make pressure go up and going up a hill makes pressure go down.

Does this sound like a bad oil pump? If so, where is it located and what does it require to rebuild, etc.

Thanks

Robert

Could be bearings. Get it checked soon.

Sounds like it could be the pick-up tube has come loose or leaking, sucking air instead of pure oil. And it could also be the pump failing, excess shaft clearance letting it draw in air.

Or it could be bearing clearance problems.

Be worth a look at the pump and pick-up tube though. The pump is in the front of the oil pan, driven off the crank gear.

While you are in there, look for glitter in the pan, that will be a sign of bearing failure. If that's there, a pump won't fix it. You can also pull some rod and main caps, look for galling, spun bearings, excess clearance. If they look good they can be Plasti-gauged to find the clearance.

If you want to try a pump, I would go with a new pump over a repair kit. It's the housing that wears, along with the gears and shaft. There may be a shim under the pump. That sets the drive gear clearance, you want some play between the gears, not binding together.

Thanks for the information. Now that I know where to look, I can try to isolate the problem. Many thanks

Robert

I always say first: hook up a second known quality gauge to the oil line and be sure you have a oil pressure related problem and not a gauge
problem, even if your gauge is near new, some cheaper gauges can give you wrong information, crud can be pumped up into the line blocking
the gauge,
With gauge unhooked turn motor over an insure you have a good flow of oil through the feeder line to the gauge

If both gauges read alike then start looking for the reason you have low oil pressure,
I run shell rotella or Valoline 15w40 diesel oil in my old tractor, holds much better oil pressure when warm, also diesel oil has zinc which helps
with long engine wear,

Might be worth a shot before you tear into the motor,

Also, what filter did you install, I always use a Ferguson dealership filter or a Napa gold filter, do not use a cheap filter,

Thanks for replying.

I used a NAPA 10/10 filter when I changed the oil. Along with non detergent 30 W motor oil.

The gauge on the tractor is old, probably the original. I traced the line from the gauge and appears to go into the engine block. I can unhook the line from the gauge. I assume then I can see if oil is coming through the line.

The oil pan has never been removed, so what problems may occur during that exercise is unknown. Testing the gauge may save some problems.

Thanks

Robert

PS

thanks for tip on diesel oil.

If the gauge was working all along, it is very unlikely to be the problem now. Worth a look, but unlikely. Using good filter, and
changing filter as you do, I agree that the Rotella oil is an excellent choice. Non detergent is good in mowers with no filter, but if
you change filter the detergent oil is probably best and the 15-40 Rotella is very popular. However, if pressure drops precipitously
when it gets hot, the Rotella oil won't solve that either imho.

(quoted from post at 22:53:21 07/15/17) If the gauge was working all along, it is very unlikely to be the problem now. Worth a look, but unlikely. Using good filter, and
changing filter as you do, I agree that the Rotella oil is an excellent choice. Non detergent is good in mowers with no filter, but if
you change filter the detergent oil is probably best and the 15-40 Rotella is very popular. However, if pressure drops precipitously
when it gets hot, the Rotella oil won't solve that either imho.

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Went out this morning to try and remove flange nut on gauge and it was stuck. Sprayed break free on the coupling and will do that for several days to see if it will loosen. I started the tractor and the gauge went to midway at which time I tapped along side of it and the gauge jumped to the right to about 3/4 mark. So it possibly could be the gauge - debris or just worn?

Thanks

Robert

Low oil pressure on the Continental Z series engines is usually due to the following: stuck open relief valve, worn oil pump, worn main bearings and any combination of these. My 1954 TO-30 maintains 27 psi at idle through max rpm, hot or cold oil and it has about 1000 hrs on a 2001 remanufactured engine and rebuilt head. Using heavier oil will increase the pressures somewhat but will not cure the problem.

(quoted from post at 19:41:02 07/17/17) Low oil pressure on the Continental Z series engines is usually due to the following: stuck open relief valve, worn oil pump, worn main bearings and any combination of these. My 1954 TO-30 maintains 27 psi at idle through max rpm, hot or cold oil and it has about 1000 hrs on a 2001 remanufactured engine and rebuilt head. Using heavier oil will increase the pressures somewhat but will not cure the problem.

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Thanks for the information. How can you tell if the relief valve is stuck open?

Thanks

Robert

PS I think this engine was worked on about 10 years ago. Not sure what was done.

You have to pull the pan. I believe the relief valve spring & piston can be accessed without removing the oil pump. The spring is held in place by a washer and a cotter pin. Removing the cotter pin and washer should allow the spring and piston to come out of the relief valve bore. You can measure the free length(should be 2 inches per the shop manual) and it should take 8.25 pounds to compress it to 1.375 inches. It"s probably easier to replace the spring. If the piston doesn"t come out then the bore is probably plugged with sludge and you can possibly use some WD40 or mineral spirits, carb cleaner, etc and a piece of wire to clean the bore and get the piston out.

(quoted from post at 22:58:58 07/17/17) You have to pull the pan. I believe the relief valve spring & piston can be accessed without removing the oil pump. The spring is held in place by a washer and a cotter pin. Removing the cotter pin and washer should allow the spring and piston to come out of the relief valve bore. You can measure the free length(should be 2 inches per the shop manual) and it should take 8.25 pounds to compress it to 1.375 inches. It"s probably easier to replace the spring. If the piston doesn"t come out then the bore is probably plugged with sludge and you can possibly use some WD40 or mineral spirits, carb cleaner, etc and a piece of wire to clean the bore and get the piston out.

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Thank you for the information. I have the owners manual but not the shop manual. I have seen those advertised on the Internet. Sounds like a good investment.

Many thanks to all that have replied and provided much needed guidance.

Robert

Consider buying the parts manual also. It"s very helpful. Together with the shop manual they will pay for themselves the first time you have a problem that needs fixing.