Fault Phenomenon: Zoomlion ZR360 rotary drilling rig veers left when driving straight.

Troubleshooting Process:
– Checked track tension: inconsistent between sides.
– Checked travel motors: severe internal leakage in right motor.
– Checked multi-way valve: travel proportional valve zero offset.
– Checked gearbox: high resistance in left final drive.

Root Cause: Internal wear in the right travel motor causes internal leakage, resulting in lower speed under the same pressure compared to the left side.

Required Parts: Repair or replace right travel motor.