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Hydraulic Oil Heat Unit Initial Starting Instructions

  • Before starting the machine, turn off the heat mode at the blower unit and make sure the toggle switch on the hydraulic unit if in the “OFF” position.
  • Start the machine and allow to run for approximately 30 minutes with only the hydraulic motor turning. This allows the hydraulic oil to fill oil the heater circuit.
  • Check the direction of the motor rotation, it must be CCW as viewed from the port end of motor. If incorrect, switch supply and return lines around on the hydraulic motor.
  • Check to see if the hydraulic oil has filled the heat circuit. A Philips screw on top of the proportional relief valve acts as a bleed port. Back out the screw two to four rotations to allow any trapped air to escape. Note: The pump doesn’t have to be turning, the case drain from the rotating motor should provide enough pressure to fill heat circuit.
  • Turn on the heater inside the cab by turning the thermostat to maximum and flipping the mode switch to heat. Note: Operating the pump prior to filling the circuit with oil can cause damage to the pump.
  • On the hydraulic unit, flip the heat clutch toggle switch to “ON”. Listen for the pitch of the pump to increase. If it doesn’t, turn the toggle switch to “Off” and check the electrical circuits, check pump rotation, and check oil fill.
  • Operate the system for at least fifteen minutes, check that the pump speed, motor speed and the hydraulic pressures fall within parameters as indicated on the Hydraulic Schematic.


Only qualified hydraulic repair technicians, fully aware of the hazards should perform the above retrofit.

Note: Kenway does not intend for these instructions to be fully encompassing.