Return to Master Table of Contents SWING SYSTEM TROUBLESHOOTING PRECAUTIONS/INITIAL CHECKS 1. Stop work. Release all weight or any type of load safely before proceeding. Avoid risking injury or adding to damage. 2. Turn off engine and disengage control functions until initial tests are ready to be made. WARNING Prevent possible injury and/or loss of operating control. Stop work and park the excavator at the first indication of: 1. Equipment breakdown 2. Inadequate control response 3. Erratic performance Stop the machine, put the boom and arm in the inoperative (overnight park) position and begin by making the fastest, simplest checks first: Check oil level.
Check for overheating, oil leaks, external oil cooler clogging or broken fan belt. Consult service record for prior repair/service work. Drain some tank oil to a clean, clear container. Look for metal shavings/grit, cloudiness/water or foam/air bubbles in the oil. Check for wobble through the engine/pump flex coupling. Run engine with the pump input hydraulic power control nut turned to the lowest power to check the engine. Investigate unusual operating noises or vibration. Check for loose bolts, connections. SWING RELIEF VALVE CHECKING AND ADJUSTMENT Make a check of operating pressures through the swing relief valve if: The swing motor fails to turn. Swings in one direction only.
Swings but continues to coast. There is drifting on a slope. 1. Check operation by connecting: A. Two 600 bar (8,700 psi) pressure gauges to the inlet and outlet measuring ports on top of the swing motor. Pressure should be between 270 - 280 bar (3,916 - 4,061 psi), with both swing locks engaged. With swing locks released, during full acceleration and deceleration, pressure should approach 250 bar (3,625 psi) in each direction. B. Connect a 60 bar (870 psi) pressure gauge at the "SH" port of the hydraulic brake. Pressure should always stay at or above 4 bar (58 psi) when operating swing, boom or arm. C. Connect a 10 bar (145 psi) gauge at the motor makeup valve.
Page 22 Hydraulic System Troubleshooting, Testing and Adjustment