Fault Phenomenon: SANY SKT105 wide body mining truck the dump body does not stop automatically when raised to the top, requiring manual forced retraction, otherwise risking hose damage.

Troubleshooting Process:
– Checked limit valve: mechanical hydraulic limit valve spool stuck.
– Checked stop block: mechanical stop block on dump body misaligned.
– Checked linkage: limit valve push rod bent or broken.
– Checked spring: internal spring broken.

Root Cause: The dump body hoist limit valve spool is stuck in the normally open position by sludge, or the mechanical stop block cannot push the valve rod, preventing oil circuit cutoff.

Required Parts: Clean or replace hoist limit valve, adjust stop block position.