Mack Truck RD688S

Measurement of the oil level must be taken on level ground.

If the engine has been running, allow about 15 minutes after shutdown for oil to drain down to the oil pan.

Is the level close to the FULL line (at least between the ADD and FULL lines) on the dipstick?

Does the level exceed the FULL line on the dipstick?

Sign off on the daily oil level check

Inspect tires for bulges, cracks, cuts, penetrations, and/or oil contamination

If any damage or uneven wear is found, the tire must be thoroughly inspected by a qualified tire inspector and repaired or discarded immediately, at their discretion.

A thorough inspection of front-end components and alignment should be performed by a qualified mechanic if uneven wear is found.

Refer to the Maintenance and Lubrication Manual, T8494, for more information.

Specific and more detailed information can be obtained by referring to the technical data books provided by each tire manufacturer.

CAUTION! For important tire information (i.e., high-speed limits, inflation pressures, etc.), consult the product information available through the specific tire manufacturer.

Inspect for oil contamination of tires

Lubricating oils, fuel oil, gasoline, and other petroleum derivatives—if allowed to contact tires—will soften the rubber and destroy the tire.

Warning! Avoid injury when checking coolant in a hot engine. Wait for the engine to cool prior to checking the level, whenever possible.

Turn the radiator cap counterclockwise to the first stop but do NOT depress it.

After the pressure has completely dissipated, press the cap downward and continue turning to remove it.

The AD6 model chassis has both a pressurized surge tank and a non-pressurized plastic coolant recovery bottle, where quick checks of coolant level can be made and additional coolant can be added to the system.

The recovery bottle is located in the engine compartment, mounted on the left-hand cab firewall bracket. Coolant should be visible between the indicator lines on the bottle.

Periodically, the coolant level should be checked by observing the coolant in the pressurized coolant surge tank. The coolant surge tank is located directly above the coolant recovery bottle. The surge tank should always be full of coolant.

The RDB and RB model chassis do not have a coolant recovery bottle. Coolant is checked by removing the radiator fill cap and observing if coolant is visible one inch below the base of the radiator filler neck.;

Warning: This maintenance check requires trained personnel with PPE!

General check for cooling system leaks

Inspect hoses and clamps for leaks and overall condition

Degree of antifreeze concentration

Is a MACK-approved winterfront used?

CAUTION! Use only a MACK-approved winterfront designed for the specific chassis.

CAUTION! Never close the winterfront if equipped with a viscous fan drive.

CAUTION! Winterfronts are NOT RECOMMENDED for vehicles that only operate intermittently in cold climates.

CAUTION! If using a coolant other than that specified by Mack Trucks, Inc., it is the responsibility of the customer to determine and perform the proper coolant maintenance procedures. Refer to the Maintenance and Lubrication Manual, T5494, for antifreeze specifications.

Filled with the proper coolant mixture

Engine run with the radiator cap tight until operating temperature is reached and the thermostat opens

Engine run long enough to ensure the system is free of air and has the correct amount of coolant

Sign off on the cooling system refilling