XCMG Truck Crane (QY / XCT) Outrigger & Boom Faults: What to Check
Cranes fail safe, which is why an outrigger that won't extend or a boom that droops needs fast attention. This covers QY and XCT families (e.g. QY25K5, XCT75).
1. Outrigger won't extend / retract
- Low system pressure → check pump and relief.
- Outrigger cylinder seal kit worn → external or internal leak.
- Control valve / directional valve fault.
2. Boom slow or weak
- Main pump wear or load-sense valve mis-set.
- Counterbalance valve stuck → boom can't hold.
- Hoist motor seal leaking under load.
3. Boom droop / drift
A boom that sags is a counterbalance or seal issue — never operate until fixed.
- Cylinder seal kit (rod + piston).
- Counterbalance valve.
4. Slew / rotate problems
- Slewing bearing worn (play or noise).
- Slewing motor seal leaking.
Order the right codes
Use the free lookup tool to confirm the exact seal-kit and valve codes for your crane model and serial, then order on TIHPARTS. Matching the code to the diagram avoids shipping the wrong kit to a job site.