https://www.truck-manuals.net/mack/ 238 MAINTENANCE AND LUBRICATION 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. Note: There is an auxiliary radiator located behind the cab that includes electrically operated fans. The fans may begin to run at any time without warning. Keep clear of fans.
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 to the first stop but do NOT depress. After the pressure has completely dissipated, press the cap downward and continue turning to remove.
Your MACK model chassis has a pressurized surge tank is mounted on the EATS rack. Coolant should be visible in the sight glass (see arrow in illustration) located on the side of the tank.
