2006 Case 750k series 2. 2500 hours To start out, the machine works great while cool. It will turn left and right on a dime. Counter rotation is not a problem. However, after coming to operating temperature temp is when the problem occurs. Left and right input from the controller to the desired direction gradually decrease until finally the dozer will not turn at all. Also, the forward speed seems to have slowed compared to the percentage indicated. 2000 hour service performed at case dealership. Regular scheduled maintanence done. Local Case dealer since shut down. Need help. Thanks
1. Any lights or fault codes on? 2. Does it turn better at speeds below 60%? It still moves forwards and reverse ok? 3. When moving forwards, do all % speeds work? (does the machine actually increase ground speed when a % higher is selected?) 4. Is the steering weak in forwards and reverse? 5. Is it overheating? 6. Do you have a ripper or a winch? 7. What is your charge pressure at an idle? Could be any number of issues. Advise on the above to help narrow it down.
1. No lights or fault codes. 2. Turns forward or reverse good until about an hour into pushing. 3. All the speed %s work as they should. 4. Steering is weak in both forward and reverse after about an hour of pushing. 5. No on the overheating. Radiator is extra clean. 6. No ripper or winch. 7. Don't remember the charge pressure, but a former Case mechanic checked it cold and said it was normal. This was after the dealership closed and the mechanic no longer had access to case diagnostic equipment, but he did have his own guages. Oh, and when I say it wont turn, I mean the tracks don't even attempt to spin in either direction when moving the joystick left or right. Pushing is also weak at that point.
I also forgot to mention, when going forward at a constant speed , then giving left or right steer input the machine slows drastically, and it doesn't turn. The motor never bogs.
I would recommend checking your charge pressure when the machine is hot. It should be at least 360psi at an idle. Since you say it steers fine when cold, I would suggest that there is a hydraulic issue. It takes a lot more pressure to make the machine turn then it does to just go straight. The most common place to lose charge pressure is from the hydraulic filter. When it is plugged, it will divert charge pressure back to tank. You may want to just change the filter. Also cut it open, and see if there is debris in it. To check your charge pressure, see the test ports on the side, one should be charge pressure. Check it at an idle when hot. You will need a 600psi gauge, or a 1000psi gauge. Then remove your park brake solenoid (it is on the left side, mounted on the tank, if you don't have long arms, you may need to tilt the cab to get to it) Try and drive forwards, and watch your charge pressure. It should drop no more than 50psi. (your park brake will be on, so don't let the machine drive through the park brake). Re-install the park brake solenoid. Advise on your results.