Fault Phenomenon: XCMG HB62K drives normally when cold. After reaching operating temperature (high transmission oil temperature), shifting is difficult, gear grinding occurs when engaging PTO, eventually unable to engage.

Troubleshooting Process:
– Checked transmission oil level and quality: level normal, not emulsified or deteriorated.
– Checked air system pressure: air pressure normal, air dryer working.
– Checked PTO cylinder stroke: normal when cold.
– Measured cylinder push rod stroke at operating temperature: found push rod stroke insufficient.

Root Cause: PTO cylinder seal ring ages due to heat, causing leakage and insufficient thrust.

Required Parts: PTO engagement cylinder repair kit.