1960 440ic Milky Hydraulic fluid

[dluxkelly]

I just bought a1960 440ic and the hydraulic fluid was milky in color. I drained the tank and flushed the system with kerosene then added new hydraulic fluid. Ran it for 15 min and it's turning milky again. Is there any obvious reason why water would be getting into the Hydraulic system?
Kelly

[Jim B]

Water maybe from adding oil from a contaminated container, cap being left off the reservoir, hole in the reservoir, or condensation for some sources. Do you have a loader or dozer? Any other attachments on it using hydraulics like ripper, backhoe, etc.? How did you flush the system with kerosene, just put it in the tank and drain it or actually run it and cycle functions? Is it a milky liquid or a frothy milky liquid? Froth can indicate an air leak on the suction side of the system.

Washing the tank out with kerosene is one thing, I would not fill the tank with kerosene, run the engine, and cycle things. The pump, valves, hoses and cylinders may well have more contaminated oil in them than was in the tank. I would plan on draining and replacing the oil (using an oil it can run on) in the tank several times to get all the milky oil out of the system. You can add some Seafoam trans/hydraulic conditioner once you get it pretty well cleaned up. A big thing is to run and work it long enough to get the oil hot to help evaporate the water out. Make sure the reservoir is vented but not open to let water in.

[dluxkelly]

Hi Jim B, Thank you for the reply.
I have a dozer with a one way blade. Moving the blade up and down is the only function of the hydraulic system. I flushed the system by draining the old fluid then added the kerosene. After that I just did what the service manual said to do and ran it a couple min but did not engage the hydraulics. After that I drained the kerosene turned the motor over for a few seconds just to get all the kerosene out. Added new hydraulic fluid and after about 30 min of running its already milky but not as white as it was before the change. It's not frothy. no water has been anywhere near the hydraulic fluid tank.

I might just need to change the fluid a couple more times to make sure all the old stuff is out. The bottom of the hydraulic tank is pretty beat up. I'm going to see if I can find a used one online and replace it.

I'll look around for leaks too. Thanks for the info!