Hi, I am new to excavators . I'm having a problem I hope you can help me with. Boom only swings one direction (to the left). It is a very basic hydraulic system, no electronics or imput values. I switched the hoses on the swing motor and , it still only swings to the left. So I thought it could be the swing motor. I removed motor and removed top. Everything looks good to my untrained eye. I then hooked all the hoses backup with the motor out so I could see if it turned both ways. It does, I then placed resistance on the spline shaft with channel locks and it still spins both ways. Any ideas? I m out of ideas. Thanks Joe
May be silly but sometimes the simple things can cause a lot of grief Have you checked under the control to make sure something is not blocking the pilot pin from pushing down for swing right direction ? Could possibly be the control stick itself, they do break and or wear out. I would start there to make sure its pushing the detent or pin in without obstruction then move on from there, could have a broken spool in the control valve or every seal and wiper on the spool wiped out. Had a few Cats in a fleet a few years apart that all would get stuck just swinging left no matter what, would work normal for hours then randomly just want to go left and keep on going. Changed out the operator valve assembly and problem solved. Believe this was around 2005 and 2006 started to see this issue on three machines with one company and two others from a different company.
Thanks for the information. I don't believe in magic, but after reinstall of swing motor. Problem stopped. Now swings both ways. When Problem first started I checked swing joystick linkage and found it was out of adjustment, adjustment rod was loose but still connected. apparently it had unscrewed I readjusted and thought this would solve the problem. It didn't. Could being far out of adjustment cause on problem in the swing motor?
Ok linkage not pilot, still could cause issue for sure. Being out far enough to have no response, I would say yes its possible as the linkage is what would push or pull on a spool residing in the control valve.