Tomorrow I need to work on a 15mp hitachi '98 ex-300 that will only high idle while walking, not while operating any other function. Any ideas? I was hoping y'all could save me some time, Thanks PJ
dig/swing pressure sensor on the swing motor failed/busted/disconnected
Ok thanks, do you happen to know which one it is or does anyone have a breakdown they could post? Also, which hoses do I swap to get it back to Backhoe controls? I haven't found a pattern changer on it
An older machine of that size most likely doesn't have a pattern changer. You might be able to change the pilot hoses between the joystick and the valve bank. Then you might be able to get away without having to adjust relief pressures.
The sensor on that model is on the top front of the valve bank. What I can almost guarantee you have going on is, the switch valve seals have blown out and allowing main pressure at the switch valve to get into the pilot circuit at the sensor. This wrecks the sensor. Quite often you can tell there is problems when the pilot line going to the swing motor has been changed. This is in the same circuit and the higher pressure blows the line. Someone then gets one made up and is usually higher pressure rating so it holds out. So what you will most likely need is a switch valve seal kit, sensor, and an o-ring for the pipe blocking access to the switch valve. Note 2" socket to get the switch valve out. Front facing on the right hand side of the valve bank. This was very very common on 300 size machines. Sorry don't have my notes handy on how to change the pattern.
Wow, thanks a ton Ken! That'll save several hours Pj