I recently bought a mid-nineties Komatsu pc300 that is stuck in high range on the track motors. Both tracks are a consistent speed, side to side and forward reverse. Speed is fast but power is low. The computer will switch the indicator light however nothing else changes. I’ve tracked the 6th line coming back from the center joint to a selinoid. My question is the flow to the motors to switch to high range or low? Can I simply cap the line and see if they will drop to low speed? Never had to deal with this before so I need some advice from those more experienced. Thanks
Mid nineties could make it a Dash 5 or a Dash 6 model? A serial number would be nice. I seem to recall that it takes fluid to put the motor in high range. Capping the hose should work. How do you know it high range? You might check cycle time on the boom up function. It should take about four seconds from the ground to top out of the boom with the stick all the way out and the bucket all the way open. That should give you a read on your pumps.
It’s a -5 yes. I’m assuming it’s stuck in high, the tracks function perfectly. Forwards and reverse is fine, lots of speed but no power climbing an incline or turning. Acts like every machine I’ve been in when in high range. It sat for 5 years before I bought it so I’m assuming the electrical side needs some love.