Inspection

4700 mm 20.01.002

Warning: Do not remove or loosen the radiator cap until the engine and cooling system have completely cooled. Use extreme care when removing the cap. A sudden release of pressure from removing the cap prior to the system cooling can result in a surge of scalding coolant that could cause serious personal injury.

Notice: Never add cold water into the system when the engine is hot as damage to the engine may result.

Every six months have the coolant mixture checked to ensure it is at the proper concentration to protect the cooling system from damage. Refer to the engine manufacturer's service literature for specific coolant information.

  1. Park the vehicle on a level surface, set the parking brake, and chock the wheels. Open the hood.
  2. The level of coolant should be between the FULL and LOW marks in a translucent surge tank (see Fig. and Fig. ) or visible through the sight glass on a steel surge tank (see Fig.). If the coolant is low or not visible in the sight glass, check the system for leaks.

    1. Surge Tank

    2. Fill Cap

    Fig. 1, Frontwall-Mounted Translucent Surge Tank

    1. Steel Surge Tank

    2. SAE Pressure/Filler Cap

    3. Sight Glass

    4. Low Coolant Sensor

    Fig. 2, Steel Surge Tank, High Flow Radiators

    1. Surge Tank Pressure Relief Cap

    2. Surge Tank Filler Cap

    3. Cold Maximum Coolant Level

    4. Cold Minimum Coolant Level

    5. Coolant Level Sensor

    Fig. 3, Radiator-Mounted Translucent Surge Tank

    3. Warning: Do not remove or loosen the radiator cap until the engine and cooling system have completely cooled. Use extreme care when removing the cap. A sudden release of pressure from removing the cap prior to the system cooling can result in a surge of scalding coolant that could cause serious personal injury.

  3. Slowly turn the SAE pressure/filler cap until it stops, to allow the coolant pressure to bleed off. Press down on the cap and turn it at the same time, then lift off the cap.
  4. While the SAE pressure/filler cap is OFF, smell the coolant for strong odors (i.e., diesel fuel). A strong diesel smell indicates that fuel is contaminating the coolant, and the vehicle must be taken to a Western Star dealer to have the source found and the cooling system chemically flushed.

    5. Note: Due to environmental concerns, it is recommended that coolant flushing and the replacement of coolant conditioners and coolant filters be performed by your Western Star dealer.

  5. Check the condition of the coolant. If the coolant shows scale, rust, silica-gel, oil, or has a frothy scum, the vehicle must be taken to a Western Star dealer to have the contaminate source found and fixed, and the cooling system chemically flushed.
Note:
Parent topic: Coolant Inspection
Document Number: 0000120208
Manual Publication Date: 2024-05-23
Topic Publication Date: 2024-10-31