Operation and maintenance manual

QSB4.5 and QSB6.7 Cooling System
Section 5 - Maintenance Procedures at 500 Hours or 6 Months Page 5-5
WARNING
Coolant is toxic. Keep away from children and pets. Dispose of
in accordance with local environmental regulations.
WARNING
Do not stand near surge tank or radiator while operating engine
with pressure cap off. If the vehicle is equipped with a fill door
on side of surge tank, keep it closed due to coolant expansion.
CAUTION
Do not operate engine with the pressure cap off at temperatures
above 200 degrees F. This can result in potential engine damage
by cavitation of the water pump and localized boiling.
CAUTION
Before topping off coolant, allow the system temperature to cool
to ambient. This will ensure that an adequate amount of coolant
is available to the water pump during all periods of operation.
CAUTION
Do not relieve the system pressure while hot in order to “top off”
immediately before returning the vehicle to service. The system
will not be able to generate the pressure through the expansion
of the coolant necessary for operation. This can result in
potential engine damage by cavitation of the water pump and
localized boiling.
Fill the cooling system with a mixture of sodium carbonate and water
(or a commercially available equivalent) to the capacity or level stated
in the OEM service manual.
NOTE: Adequate venting is provided for a maximum fill rate of 19
liters [5 gal] per minute.
Unless indicated otherwise by the 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 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.
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.
Operate the engine at HIGH idle until the thermostat opens.
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.
Turn off the engine and check the coolant level according to the OEM
service manual recommendations and add, if necessary, to bring it
back to the FULL level.
Install the cooling system cap.
Operate the engine for 1 to 1½ hours with the coolant temperature
above 80°C [176°F].
Shut the engine off. Allow the coolant temperature to drop to 50° C
[122° F] before draining the cooling system.
Drain the cooling system.