I've been trying to get my dad's excavator back running after she sat untouched for 7 years after sliding into our dam. Current problems I'm facing.... Had hydraulic fluid leaking from turntable, pulled rotary union, had seals and o rings replaced at hydraulic shop. Had water in hydraulic fluid, drained tank, cleaned filters, and refilled. I've also had a few burnt wires on relays for the EC. Fixed those. I ran it to check for leaks. My swing worked to begin with then stopped. Also my hydraulic fluid seemed really hot. Shut it down, checked swing device oil, it was fine, no mixed fluids. Crunk it back up had swing, tracked about 15 ft, lost swing, now hydraulic fluid is leaking from turntable. I believe I have an electrical problem, either causing pilot pressure switch to not work correctly or solenoid. If so could this overload my pressure to my rotary union? There is a hose that feeds either to or from the swing pump to the rotary union. Or could I have a blockage in a line somewhere. The suction filter in the bottom of the tank was really gummed up.
There should be no connection between the swing motor and the swivel, except for the case drains might get routed together back to the tank. That is all that I can think of. If the case drains run together like that, if it gets plugged on the way to the tank then you get a buildup to system pressure in the case drains. That is a bad thing overall. If the swing motor is really gushing out the case drain because it is shot, that can build up some pressure where it should not be.
Could I unhook it and fire it up briefly to see?
yes put the case drain from the swing motor in a bucket. It should be next to nothing coming out of it. If you swing and it gushes, there you go.
Thank you. I'll see what it does
Also, could this cause my hydraulic cooler to not function properly
The screenshot below shows the proper routing of the propel motors case drain hose key #59A and the swing motor case drain hose key # 63A. Also do you have a machine serial # ? .
1ew-033080 I've been told it's a gray machine
Screenshot below shows the proper hose routing of the propel speed shift hose key # 22A and the swing brake release hose key # 26 . .
Interesting … an EX120-2 the serial number prefix is 12N . Could you take a pic of the serial plate ?