A friend of mine asked me to take a look at his PC200 LC-3 because it wont swing, I checked the brake pressure and no oil pressure was at the brake, it was barely pouring out of the hose. The brake hose runs down to an electric valve that has what looks like a drain hose and a hose that runs to the bottom of the valve body. I have no books on this machine I was wondering if anyone had any advice for me. Thanks
You can check out http://komatsupartsbook.com/ . They have exploded parts views for that machine, may help in the disassembly.
Is a filter clogged somewhere in the hydraulic system leading to it? Just a thought.
Somewhere in the cab there is a bypass switch that will energize the solenoid and send pilot oil to release the brake. The bypass is usually under the glove box that you lift out of the consul. There should be two toggle side by side. As I recall the one on the window side is the brake bypass and the inside one is the computer bypass for the pumps. If you have a gray market machine you might have to pull the side cover off the consul on the right side. If that doesn't work you will need to check the solenoid coil with an ohm meter. There should be at least two ohms of resistance. When they fail they usually short through and read no resistance or burn out and have infinite resistance. If the coil is good and you have shifted the bypass toggle switch the you probably have a wiring issue. That is pretty normal for machines as old as this. If it's wiring you will have to work out a fix on your own. I have pulled harnesses out and cut them out of the tape to find and fix the problems. I have also run new wires outside the harness to get machines working. Good Luck!