SHAFT AS 7V4217 - Caterpillar

Use the Cat® Electronic Technician (Cat ET) Service Tool or the machine monitors to check for active diagnostic codes. If any diagnostic codes are present, refer to the appropriate diagnostic code troubleshooting procedure to correct this problem before continuing.The swing brake engages when pilot pressure is removed from the swing brake motor. When pilot pressure is applied to the swing brake, the brake is released and machine swing is allowed.If the machine swings normally, and the machine passes the Testing and Adjusting, KENR9615, "Swing Speed and Swing Drift on a Slope - Check", the swing brake system is operating correctly.If the machine does not swing and swing left or right workport pressure increases when swing is commanded, the swing brake is likely not receiving pilot pressure. Swing pressure can be found in the monitor. To verify the swing brake functionality, proceed to the following test steps:
Verify that there are no leaks in the pilot lines to the swing brake.
Verify that pilot pressure is within specifications provided in Testing and Adjusting, KENR9615, "Relief Valve (Pilot) -Test and Adjust". Use the procedure to adjust pilot pressure if necessary.
Shut off the engine by turning the start switch to the OFF position. Lower implements and perform Testing and Adjusting, KENR9615, "System Pressure - Release".
Place current shunt on solenoid that controls pilot signal to swing brake. Use long Multimeter probes to allow monitoring from a safe location.
Start the machine. Command a bucket curl with the joystick. During any joystick command, voltage should be supplied to the swing brake solenoid. If the voltage is below 18V during joystick command, inspect the harness for shorts.
If voltage is supplied to swing brake solenoid but the machine does not swing when commanded, replace the swing brake solenoid valve.