Komatsu PC150LC-6k Hydraulics start to flutter then barely move, then have to hit bypass switch.
Only one particular function or are all functions affected when the problem occurs?
Seems to be all
When first running it operates normally, it starts happening after running especially when the outside temperature is higher.
Once the fault occurs and you switch the bypass/prolix switch over will the machine operate as normal or does it still appear to flutter and have the same performance issues?
It doesn’t seem to have any issues. I think it just runs a little slower once the bypass switch is moved, but it seems to have no other issues and I can run the machine just at a slower pace then as if it was running normal.
If the fault occurs when the hydraulic operating temperature begins to heat up, then it could be a possible bypass in the main pump or its Load sense control. You will need to check the LS Control EPC solenoid valve for its correct electrical and hydraulic operation. From there it would be a good idea to check the pumps performance with a flow meter with a loading valve and reference the readings against Komatsu specification. Try inspecting the hydraulic return filters in the hydraulic tank and also the main pumps case oil by draining it into a clean container and doing a visual inspection for large amounts of metal contamination. If you find a lot of metal it would be best not to test any further, strip the pump for inspection and clean out the hydraulic tank. Best regards
Would you know the location of the LS Control EPC solenoid valve? Thank you for the advice, and taking the time to respond to me. I appreciate it.
Mr.Kobe Steel...So sorry! but I think it's the fault at TVC EPC, not LS EPC.
No problem, always glad to help where possible. You may find this valve on a manifold either by the main control valve area or sometimes in the pump bay, sorry but I could not find a diagram in my information that shows its location. Best regards
No need to apologize Lachau, your help and technical input is much appreciated by myself and others here. Thank you sir.
Sir, would you possibly have this diagram in the PC200-8? LS-EPC or PC-EPC. or either one
Was this issue ever resolved? I have a PC200-LC6 that gets slower as it heats up. It throws codes regarding TVC disconnected for both pumps but testing shows good solenoids and proper resistance in the wiring checks. The wiring connectors at the pumps have desintegrated with time, temp and oil, along with lots of insulation. These wires have been re-wrapped and reconnected at the TVC valves but I am still having the same issues. I can not find my parts manual to identify which wiring bundle is associated with this mess. Serial #A80880. Does anyone know if the buzzer is supposed to sound and stay on when the prolix switch is turned on? The machine runs faster with the prolix on but it is still much slower than it should be. No strange sounds from the pumps. Pressures, according to monitor, are lower than expected. When you open the pump door, look for the small solenoid valve on the lower right corner near the outer edge. That's it there. Mostly small control lines running to it and a single solenoid.
I replaced that solenoid valve and stopped getting the code and the slowdown. When I removed the solenoid valve from the pump, it was seized and not moving. It would mostly give me trouble when the temperature outside was hot. But we’ve had some hot days since I replaced it and have not had that issue since.
Good to have sent back the solution you found for others benefit, more may benefit without you even knowing. Simon C
Glad to help