MAINTENANCE AND LUBRICATION 249 COOLING SYSTEM The cooling system is a pressurized system. The coolant is circulated by a centrifugal pump. It is a typical system in most respects, but there are a few things to keep in mind when checking or working on the cooling system.
WARNING Keep clear of fan when engine is running. Fan may start to rotate at high speed without warning.
WARNING Avoid injury when checking coolant in a hot engine. Wait for the engine to cool prior to checking the level whenever possible.
Coolant Level Check
WARNING Turn the cooling system pressure cap counterclockwise slowly. After the pressure has completely dissipated, continue turning to remove the cap.
Your MACK model chassis has a pressurized plastic coolant expansion tank where quick checks of coolant level can be made and additional coolant can be added to the system. The expansion tank is mounted on the radiator. Periodically, the coolant level should be checked by observing the coolant in the expansion tank.
