07/25/2024
Komatsu CK30 was running fine, until the operator dumped in the stockpile. When backing up, the tracks quit moving. All hydraulics worked, and the pump whined when trying to track, but the tracks would not turn. Initial diagnosis revealed that the parking brake solenoid was shorted at 0.4 ohms. But additionally, there was no power to the park brake solenoid. With the park brake solenoid replaced, the next task was to figure out why there was no power to the brake release wire. Testing led to the interlock module. Luckily this module allows for disassembly, and a burnt trace was found on the PCB. The interlock module was replaced, and then the brake release wire was energized. Kind of.
Amazingly, this machine was running for an unknown amount of time with a MISSING park brake release relay. No idea how it had been working. New relay installed, machine tracks normally!
