Case 850k series 1 left track will not move. Right track operates correctly. Fuses/relays good. Cleared faults and no faults come up. Thinking its the left motor or final drive but dont know how to check them. Any ideas? Any help will be greatly appreciated.
Dozer will load up and bog down when trying to move left track but sprocket won't move at all.
Sounds like a brake problem you may want to check to see if you are getting pressure to release brake, sense it is a spring applied pressure release brake.
Theres a line that leaves a solenoid valve behind the battery and goes to the left final drive then tee s and goes to the right final drive. Should I just tee into that line to check the brake pressure? Also what kind of pressure am i looking for?
Yes you can check brake pressure there by teeing in a gauge. I don't remember what the pressure is or should be.
Ok. I was just thinking it was good because the other track was working fine and that solenoid line is common to both there in parallel. Do you know if it uses the fluid in the final drive to actually deactivate the brake? The final drive does have a leak on it were going to check the fluid next time we get a chance to work on it.
We checked the left final drive fluid. When we pulled the fill plug fluid was coming out of it We drained it and drained about 6 gallons. Its only supposed to hold 3 gallons. There wasnt any metallic in the oil. There was small pieces that looked like dirt or a gasket you could crumble them up in your hand. Were thinking oil is leaking by the pump or brake circuit?
It sounds like the shaft seal in the drive motor is bad and putting hyd. oil into final drive.
Had a few minutes to work on dozer today. Pulled the line off the brakes from the brake solenoid valve. Had no pressure with dozer running and parking brakes up or down. Disconnected solenoid valve and jumped it to battery you can hear a very faint click. Coil ohmed out good. Going to get a better test setup and jump brake solenoid to battery with the dozer running next time we get a chance to work on it and see what it does.
The right track brake must not work because it will still move with the line disconnected
If you can connect the two hoses together at brake valve and see what happens.
Conected the feed and brake hoses together. It gave me around 300 psi to the brakes still same thing.
The brake may have melted together and will not release so you will need to take the cover off on top of the final drive. You may have to remove one or two track pads to get cover off.
We already pulled the cover off to see if anything was broken. Everything looked fine. Checked the coil on the left drive motor. It ohmed out good. The ground wire going to the harness going to the coil ohmed out good to ground. We tried to check the other wire for 12volts while trying to move the track and got nothing.
Did you take brake parts out and try the drive motor then to see if it worked?
Tilted the cab and dropped the belly plates. The solenoids on the hydro pumps where covered in dirt. Both coils on the left side ohmed out bad "shorted" Both on the right side ohmed out good around 5.75 ohms. One of the bad ones the insulation was gone off the wires a couple inches back from the connector. The other bad coil you couldnt see anything visibly wrong with it.
I hope what you found was your problem. Sorry I didn’t think of that earlier.