Cummins Diesel Engine Replacing Fan Drive Hydraulic Motor

Leaking input shaft seal

The fan drive [Made by DANFOSS} on a Thomas school bus is a hydraulic motor run by a control module that reads engine temperature. The fan assembly is tranversely mounted. One advantage of having a hydraulically actuated drive is there are no belts.

The Cummins diesel in this application is an ISC 8.3 model. The power steering oil used is 10w30, once drained disconnect all hydraulic hoses. The fan blade must be removed and rested against the radiator.
Once the motor is removed the fan hub must be removed using a suitable puller, the motor shaft is tapered.

DID YOU KNOW? The difference between a hydraulic motor and a hydraulic pump?
A hydraulic pump{steering pump} supplies oil flow driven off a diesel engine while a hydraulic motor operates a device {in this case a Diesel Engine cooling fan} and is driven by the hydraulic pump.

Once parts are exchanged the reassembly is straight forward with a little bit of manuevering. Add oil and change steering filters if required. Perform running checks and your are done.