I have a Komatsu PC50. This morning, the hydraulics started a problem. SAE configuration (hasn't been changed in years) I push the dipper stick out (left control stick forwards), then, when I pull the stick in (left control stick backwards) the boom goes up. To make the boom go back down, (and pull in the dipper stick), I have to do another weird combination. When either of the moments are happening it is super slow. Hydraulic filter was changed about 100hrs ago, same with fluid. No leaks, no visible signs of damage, etc. All the other controls are working fine - ie. bucket, swing, track, blade.. I traced the 4 lines for the boom and dipper stick hydraulic pistons back to the main control valve. I noticed they are right next to each other. I'm thinking the valve inside is stuck, causing this crossover of fluid... but before I tear that open, I'd like to try to get some other opinions. A friend said maybe a relief valve is stuck... but I don't see how that would cause this problem. any help is greatly appreciated.
Is there any kind of pattern changer valve on it that may be leaking inside or has gotten bumped out of position
No leaks I turned the pattern changer both ways.. full stop. No difference
Then I would think it's bypassing inside. It should change the pattern if you move it. It only affects boom and stick.
yeah, that is a really good point. I wonder if I can re-plumb and by-pass the pattern changer to eliminate if that is the problem or not.
all fixed! i must have been in super retardo mode yesterday. I had turned the aux valve, not the pattern changing valve (thinking it was the pattern valve). The pattern changing valve had vibrated to a middle position causing the f*ed up controls. I really appreciate the feedback, mobiltech.. you saved me on this one.
Можете ли помоћи за мој спори pogon gusenica na komatsu pc 50. Mogu ppslati snimak kako to izgleda.. hvala