Fault Phenomenon: Sinoboom TB26J telescopic boom aerial work platform after continuous operation, the hydraulic oil temperature alarm sounds, system automatically slows down.

Troubleshooting Process:
– Checked radiator fan: fan not spinning.
– Checked radiator surface: surface clogged with catkins and dust.
– Checked hydraulic oil viscosity: oil deteriorated.
– Checked relief valve: system in relief state for extended period.

Root Cause: The hydraulic oil cooler fan motor is burnt, causing loss of cooling.

Required Parts: Cooling fan motor assembly.