I have a 2010 case cx135 that runs really good when cold.Once the machine warms up(usually about 30 min)the track on one side goes into turtle speed.The machine travels in high no problem when cold though.The same track does it going forwards or backwards.When it starts to act up ,if i over correct to one side, it will travel in high until i have to straighten it out and then it starts off in low.I know it goes to low speed because when it acts up i ease up on the pedal going faster so that it travels straight ,then i hit the switch for low travel speed and the speed stays the same .When i travel in low the machine walks perfect and does not act up at all.
These machines are self load compensating, meaning that it will shift to low speed automatically when too much load is on the travel motor. With that being said, I had one doing the same thing, and it ended up being the travel motor. The motor itself was fine, but the 2 speed piston was worn out. There was too much leakage between the piston and the bore. There is no seal for the 2 speed piston, so we had to change part of the housing. I'm sure you could also machine a new larger piston. If you have the bad track raised in the air does the 2 speed work on it? (when its hot and the problem is happening)
Yes the 2 speed works if I raise the track.How did you finally narrow the problem down to the piston and is there a way to test it before tearing it apart.Thanks for your help.
Well, there is a series of short tests you can do. Since the travel motor works while under little load (in the air) and while its cold, it suggests a leakage/bypass problem in the 2 speed piston. 1. Check your pilot pressure. Its suppose to be 568psi 2. There is a pilot screen on the travel pedals. Check for debris. Switch the output lines on the travel pedals. You have to be getting full pressure to fully stroke the travel spools. Run unit and test to see if travel issue changed sides. (remember controls will be backwards) 3. Check the 2 speed pressure at the travel motor. Should be equal to charge pressure. Check when moving, and when not moving. See picture below. If all of the above checks ok, I would look at 363 and 161 in the motor.
Thanks for your help Gary.I switched the output hoses on the pedals and the same track started acting up when it got warm.I am still using the hoe and wont have any access to gauges for a few days so I will do some testing in a week or so and see if the pressure is right.