Komatsu "Four" (safety) System

[johnnyg]

Hi postmortem_42

I final got to try wiring all 4 solenoid to the bypass switch , oddly it blow a 20 amp fuse behind arm rest right arm , but the by pass switch still has power afterwards oddly . There only one potentiometer on the boom connected.The very first pipe to aluminium block is disconnected oddly I don't see a joiner. You mentioned PCP could be burn out can you advise some more please of your experience of this is this pilot control pressure for short

 

[postmortem_42]

only three go the the bypass, the fourth (closest to back) should be wired to key on and not to bypass switch. This solenoid is associated with the PCP feed and should be key on wired. All others control boom, arm and offset and have both and in and out of the block.

 

[johnnyg]

Thanks a mill , I will try that

 

[postmortem_42]

just make sure you maintain a feed to and return from the junction block.

 

[Spadman]

I’m trying to replace the potentiometer on the arm of my PC50uu2. The position of the lever as found on my machine doesn’t seem to be correct. Can someone who has this machine look at this picture and compare it to your machine? I found a drawing in the service manual that has the pivot arm oriented to the right side rather than the left. Thanks.

 

[oldtom]

John C will have more detailed knowledge on the system on your particular machine but a function running slow then running at normal speed when operated in conjunction with a 2nd function is usually the result of a problem in a resolver (shuttle) valve somewhere in the main control valve. The function of the resolver valves is to prioritize hydraulic supply to functions.

Hey Nige you've been around 428 tooo long