Operation and maintenance manual

Cooling System QSB4.5 and QSB6.7
Page 5-6 Section 5 - Maintenance Procedures at 500 Hours or 6 Months
WARNING
Do not stand near the surge tank or radiator while
operating the engine with the pressure cap off. If the
vehicle is equipped with a fill door on side of the
surge tank, keep it closed due to coolant expansion.
CAUTION
Do not operate the engine with the pressure cap off a
temperatures above 93°C [200°F]. This can result in
potential engine damage by cavitation of the water
pump and localized boiling.
NOTE: Do not install the radiator cap.
Fill the cooling system with good quality water to the
capacity or level stated in the OEM service manual.
Unless indicated otherwise by OEM instructions, it is
critical that all shutoff valves be returned to their open
positions once the system has been refilled and the
deaeration process is about to begin. This will help to
make sure as much air as possible will be purged from the
cooling system. See the OEM service manual for valve
locations.
Wait 2 to 3 minutes, without starting the engine, to allow
the system to naturally purge entrained air and the coolant
level to stabilize.
Add plain water to bring the level back to FULL.
Turn all cab heater switches to HIGH in order to allow
maximum coolant flow through heater core(s). The blower
MUST be turned ON.
With the cooling system fill cap removed:
• Operate the engine at LOW IDLE for 2 minutes.
• Turn off the engine and add plain water to bring the
level back to FULL.
With the cooling system fill cap removed:
• Start the engine
• Operate the engine at HIGH IDLE until the thermostat
opens.
NOTE: After starting a cold engine, increase the engine
speed (rpm) slowly to provide adequate lubrication to the
bearings and to allow the oil pressure to stabilize.
Allow the engine to return to LOW idle for 2 minutes
before shutting it down. This allows adequate cool down
of pistons, cylinders, bearings, and turbocharger
components.