Heavy Equipment Repair Questions? Ask an Expert Now.
That is the spec for normal drives to engage.
Steering response is different. Below are some of the guides they will use to check the machine.
The machine does not move correctly when the pilot operated hydraulic control ( hydrostatic) is actuated.Probable CauseThe speed sensing valve may not be set correctly.The charge pressure is too low.The pilot operated hydraulic control ( hydrostatic) may not be functioning correctly.The orifices at the pilot operated hydraulic control ( hydrostatic) may be plugged.The piston motors may be worn or the pumps may be worn.
The machine is not modulating correctly.Probable CauseThe oil temperature is too low.There is a restriction in one of the pilot lines.The pilot operated hydraulic control ( hydrostatic) is not functioning properly.The piston pump is worn or damaged.The piston motors are worn or damaged.
The machine does not track straight.Probable CauseThe neutral null setting is incorrect.The pilot operated hydraulic control ( hydrostatic) is not functioning correctly.One section of the piston pump could be malfunctioning.A piston motor may be malfunctioning.The displacement stops on the piston pumps may need adjustment.The orifices on the pilot operated hydraulic control ( hydrostatic) may be plugged.
My guess is they will focus on the joystick control.
Both joysticks have the same source for pressure, both would have problems if it was from the source.
Yes, anything can happen to a line to cause it to block flow. If you have damaged anything or had a fire in the recent history, I would follow up on those repairs first.
Trash from a damaged hose can plug orifices. Sticking servo controls would plague Case units but, I have not seen that on Cat.
Please send me your serial number and I can check for service letters.
I hate to second guess another tech but, this system is pilot hydraulic controlled. The ECM only serves as an interlock safety control. This prevents the machine operating without the safety bar down, an operator that weighs over a hundred pounds and the park brake switch released. Options for auxiliary controls will have a second ECM to switch flows and operate attachments.
I have not seen any speed or steering electronic controls on the B models. The only electric function is the on/off solenoid for each joystick. This simply sends or blocks oil flow to the joystick based on the command from the Interlock ECM.
It can cause the delay in starting to move if you press the park brake switch and try to move at the same time. When you release the joystick and it returns to center, the oil flow in the joystick is dumped to tank and the machine should stop moving.
I may be missing something here but, be sure to test run the unit before you pick it up from the dealer.
Yes, I can see how it would be sluggish to start to move and weak steering input. I don't see how it would cause it to not stop moving. The machine should always stop quickly when the joystick is centered.
Replacing the joystick and the ECM would cover both problems.
Thanks for the update. I wonder why they would not try the valve first?
I would push the issue a little. They could offer a goodwill policy adjustment or keep the new ECM as a shop tool to use as a test ECM. We have a couple of different models just for that purpose.