Just purchased. 4,200 hours. Changed every fluid and filter. Used about 2 hours and lost all steering suddenly. Worked perfectly prior. Everything else operational. Brakes are still good. No leaks. Has joystick steering, not hand levers. Linkage from joystick in place. Unsure where to start. Any help appreciated. Pump issue or steering control valve or ??? Thank you!
Update - Left sitting overnight. Worked perfectly the next morning but once again lost steering after light use for about 20 minutes. If I hold joystick either way it will eventually, slightly grab and turn momentarily.
That sounds like a worn out pump more than anything else. I wish I had a service manual on the machine to help you out with. Does this machine have a torque converter or is it hydrostatic drive?
Torque converter. I've only had one hydraulic pump failure ever on a machine and it just completely stopped working so was unsure if this is what it could be.
That's good information. When your machine is working properly, can it counter rotate the tracks?
I have not tried to counter rotate, but either track will completely lock up if you want it to. Thanks John
I'm looking to find out if you have steering clutches or differential steering. Differential steering uses a steering pump to vary track speeds on a mechanical drive. Komatsu and Cat machines started using this sometime ago but some of the Komatsu machines were Dressta machines that stayed with steering clutches and brakes.
So there's a steering steering pump that that is driven off the torque converter. The linkage from the joystick goes back to the steering control module. I'm sorry but unable to answer your question for certain .
I don't believe it's differential steering.
If it will counter rotate tracks it will be a differential steer machine. If moving the joy stick only affects one track at a time it will be a steering clutch and brake machine.
It's definitely a steering brake and clutches . Thanks for clarifying
To troubleshoot the problem you are going to need to install a gauge into the steering system and watch what happens to the supply pressure while you are running the machine. You possibly have two issues. The first is the condition of the steering pump and the second is possibly a problem with the steering control valve under the joy stick. I've rebuilt that valve on a similar machine but the problem wasn't with the steering on that one. It was with the shifting speed ranges of the transmission. We can work from there.
those steering pumps are tempermental they pull the oil from a long ways