Operation and maintenance manual

QSB4.5 and QSB6.7 Coolant Level
Section 4 - Maintenance Procedures at 250 Hours or 3 Months Page 4-5
CAUTION
Do not add cold coolant to a hot engine. Engine
castings can be damaged. Allow the engine to cool to
below 50°C [120°F] before adding coolant.
Coolant added to the engine must be mixed with the
correct proportions of antifreeze, supplemental coolant
additive, and water to avoid engine damage.
Coolant recommendations and specification details on
correct mixing of coolant can be found in Maintenance
Specifications (Section V).
Fill the cooling system with coolant. Refer to the markings
on the radiator or expansion tank for coolant levels or
refer to the OEM manual.
NOTE: Some radiators have two fill necks, both of which
must be filled when the cooling system is drained.