Water in hydraulic fluid

I have a 1998 JD 650g and noticed my fluid was milky. Dont know how it got that way but was wondering if it could come from radiator or any other fluid. Have not had dozer but a couple of months and it has 7000 hrs on it. It was serviced and washed before they delivered it to me and it could have got water in it when they washed it. I dont know just trying to narrow my options before i drain fluid and flush system 2 to 3 times. Thanks for any help

I dont believe the hydraulic system and radiator are connected where it could leak into each other, however if you check your antifreeze and its murky and has oil in it then that'll answer that question since the hydraulic system is under more pressure than the coolant. more than likely water got in through a hose laying in water with a small hole or dry rotted and some water seeped in, or the cap let water in when it was pressure washed. another more common issue is that it was low and someone added hydraulic fluid that had some moisture in it and i foamed up after going through the pump. id drain the little bit of hydraulic fluid thats in the tank and add fresh oil then run it and let it sit. then before you run it drain off any accumulated water in the tank and add fresh oil to hopefully get all the water out eventually.

Yeah when i look at radiator it does not look like they are connected it looks like 2 seperate radiators. A small one for the fluid and the regular for the cooling. The radiator for the cooling is a little low but it looks like regular antifreeze. It is a little low and i can touch inside where its low and there is a greasy white/grey residue that you can wipe with your finger and thats what has me worried that they are connected some how even though the antifreeze looks fine.

I've seen rainwater leak into a cylinder while it is not under pressure. If the wiper seal is worn, and the cylinder is oriented with the rod sloping up even slightly, water runs right down the rod to the wiper and under it. Then the worn pressure seal, which was made to expand and hold pressure from inside, and with the weight of the cylinder hanging on it leaving a gap on the bottom, allows the water to seep by. Had that on a backhoe and it drove me crazy trying to figure out how the hydraulic system was getting wet. The leak was noticable for a few minutes but would stop so I just lived with it. I could work that backhoe for a few hours and the moisture would be driven out.

If hydraulic fluid leaks out of any cylinder when you first start using your 650G, that might be the culprit.

Bob

Well i found out for sure that the water from the radiator can not mix with the hydaraulic oil and drained the oil out and added new oil and bleed the lines at the cylinders. Oil got a little milky again so i drained it again and bleed it till it got clear and its been clear ever since so i really dont know how it got there but atleast its out and its not a radiator problem. Thanks for the help.

As a comment the inside of the radiator should not be greasy. Maybe at some time in the past there was a cylinder head gasket or an engine oil cooler failure and there are still traces of contamination from that event..?

Either way I would suggest a complete cooling system flush and clean of the system with non-foaming detergent the next time you consider replacing the coolant.

ALslamma52 said:

Well i found out for sure that the water from the radiator can not mix with the hydaraulic oil and drained the oil out and added new oil and bleed the lines at the cylinders. Oil got a little milky again so i drained it again and bleed it till it got clear and its been clear ever since so i really dont know how it got there but atleast its out and its not a radiator problem. Thanks for the help.

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There are a couple things that I would do since this is a relevently new machine for you.

Clean out the radiator and the block like Nige suggested. And then sample the engine oil and coolant after running it for around 40-60 hours. You'll want to look for cross contamination.

Second for the hydraulic oil taking on water. Ensure that the contaminated hydraulic fluid is well drained to include the cylidners. I would put a condensent hydraulic filter on and you'll need to change this a few times until all of the water is caputred. Once the moisture is out I would sample the oil using the Karl Ficsher test and it will give you the exact water content in your oil. Sample at 60-80 hours later after the KF test results comes back and compare the results. This will tell you if you are taking on water in your hydraulics and then you will know you will NEED to find the leak.

Are you sure it's got water in it and not foamed up from air getting in the suction hose? We had a 555g that would foam the hydrolic tank and found out it was the clamp that connects the hose to the tank. Gave it a couple of cranks and the problem went away.