C and hydrolic pump

[Johnny D]

I noticed the C i bought was about 4 quarts low of hydrolic fluid. After filling to required level and running her for while my oil pressure started to drop a little at a time. What was happening according to the old guys is that the hydrolic fluid was being pushed into the oil. It also has a bad leak on the hydrolic unit itself. No visible leaks on the pump. I was told that most likely I would need to replace the gasket that is between the hydrolic pump and the engine to stop if from leaking into the oil pan. And it looks like i need to rebuild the hydrolic unit as well to stop the exterior leak on it. Any other helpful information is appreciated.

 

[Peabody]

There is no gasket between the pump and the engine. Your problem is most likely the seal on the pump shaft, which allows fluid to enter the engine oil pan. A rebuild kit is available and will probably solve the pump leak also. It's an easy fix. I'm not sure what this would have to do with an indicated drop in oil pressure, though.

 

[Johnny D]

Since the hydrolic fluid is mixed with the engine oil the old timers claim it makes the oil thinner which causes the slight drop. Just wondering if true. It sounds good. I know that I gained engine oil while running it.

 

[georgeky]

Johnny, there is a seal in the front of the pump that is bad. The shaft may also be worn and need a speedy sleeve put on it. Use only sae 30 weight oil in the hydraulic system until you get this fixed. Hydraulic oil is to thin for the engine. Seal and gasket kits are available from IH. There are 3 different pumps it could be so you need the part number from pump when ordering kit. The lift unit itself has a kit available for it as well. Keep it clean and lay all parts out in order they come out. Makes putting back together a lot easier. Get an IT No IH-8 service manual as it will be needed for proper adjustment of the lift unit. Not real hard to do, but cleanliness and proper adjustments are critical. Call Brad Marshall and he will send the parts you need right to you. 1-888-824-0544.

 

[georgeky]

Hydraulic oil is only 10 weight. That will cause a drop in oil pressure.

 

[Peabody]

Not true. Liquids, however thick or thin, cannot be compressed. Pressure will remain constant regardless of viscosity.

 

[georgeky]

Johnny, check your engine oil. It should be over full if hydraulic oil is getting in there. Also normal for Farmall tractors to loose quite a bit of oil pressure when they are at operating temps.

 

[El Toro]

Here's a parts breakdown on your pump. Hal

 

[Janicholson]

Oil is not compressible, but mixing thin oil into regular engine oil will allow the mix to escape through the bearing edges and openings faster resulting in lower pressure for sure. Imagine a can of oil open on top with a 1/8" hole in the bottom. When filled with 90wt gear oil it takes 1 minute to empty. With 3_N-1 oil in it it would empty in 15 seconds. The tractor is not compressing the oil, it is pushing it through orifices and bearing clearances. JimN

 

[georgeky]

You put 10 weight oil in your tractor and run it until warm. I will guarantee your oil pressure will drop a bunch. Has nothing to do with compression of liquids.

 

[Johnny D]

George,
So it is ok to use SAE 30 in the hydrolic system now? After it it fixed, what would you recommend?

 

[jonny2006]

peabody george is right. thin oil will make its way thru tighter clearances......Thats why todays cars require 5 weight or even 0 weight. this is because higher visicoty oil will not lube the bearings in todays engines per manufacture specs. alot of forigen cars reqiure 0 weight oil. In all my cars and trucks I run castrol syntec 5-50 weight. It will lube the vital engine parts eeven when it is -20 and makes for easyer starting.. Plus thre oil will not break down in extream temps. inother words you get all the benifits of a "5 weight" oil when its cold and "50 weight" oil when the engine is under extream temps. best of both worlds. I would not run it in a car that has a oil leak as it is 6 bucks a quart.

 

[georgeky]

Yes, 30 weight will not hurt a thing. I would use non detergent SAE 30. That is all I ever use in mine, and they don't leak into the crankcase. Also use SAE 30 in all my Letter series Farmalls.
Once you get it fixed you can use Hy-Tran, 10 weight or AW-32 hydraulic oil or even the 30 weight. 30 is a bit stiff for use during the winter if it gets cold where you are.

 

[Johnny D]

West TN and it usually doesn't get into the 20's if only for a few days.

 

[NawlensGator]

As you open a valve on the dishcharge of a pump, the discharge pressure will decrease as the flow increases. If you close the valve completely the discharge pressure will be at it's maximum, or 'dead head pressure'. Similarly, thinner oil results in higher flow and lower discharge pressure. The higher flow results from reduced frictional pressure drop through small clearences. Reduced friction is due to lower oil viscosity of the hy-tran. This is not good for the engine which requires the lubricating ability of higher viscosity oil. I would get this fixed before operating again.

 

[Peabody]

OK, I slept on that one and realized I was wrong. Has nothing to do with compression of liquids.

Gosh, you never stop learning, do you?