303.5E2, 304E2, 305.5E2 and 305E2 Mini Hydraulic Excavators Engine and Machine Warm-Up Caterpillar

Illustration 1	g00818250

Note: The hydraulic lockout control (lever) must be in the UNLOCKED position before the hydraulic controls will function.

1. Allow the engine to warm up at low idle for at least five minutes. Engage the joystick controls and disengage the joystick controls. This will speed up the warm-up of the hydraulic components.

   When you idle the machine for warm-up, observe the following recommendations:

   • If the temperature is greater than 0°C (32°F), warm up the engine for approximately 15 minutes.

   • If the temperature is less than 0°C (32°F), warm up the engine for approximately 30 minutes.

   • If the temperature is less than − 18°C (0°F) or if hydraulic functions are sluggish, additional time may be required.

2. To warm up the hydraulic oil, turn the engine speed dial to the medium engine speed. Run the engine for approximately five minutes and move the joystick intermittently from the BUCKET DUMP position to the HOLD position. Do not hold the joystick in the BUCKET DUMP position with the bucket cylinder fully extended for more than 10 seconds.

3. Turn the engine speed dial to the maximum engine speed and repeat Step 2.

   This allows the oil to attain relief pressure, which causes the oil to warm up more rapidly.

4. Cycle all controls in order to circulate warm oil through all hydraulic cylinders and all hydraulic lines, and through the swing motor and travel motors.
   Show/hide table

   When you cycle the machine controls, the machine can move suddenly. Contact between the machine and external objects or ground personnel can result in serious injury or death. Before you cycle the machine controls, the machine should be located in an unobstructed, hazard-free work area that is away from external objects and ground personnel.

5. Observe the gauges and the indicators frequently during the operation.