Service Manual

ISB, ISBe and QSB (Common Rail [...] Cooling System
Section 8 - Cooling System - Group 08 Page 8-41
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Figure 1: Sequence of Events for Coolant Fill and Deaeration.
NOTE: If all coolant drained from the system was collected, the same volume or more must go back into the system.
If any drained coolant remains after filling, this is an indication of an air pocket which must be purged before returning
the vehicle to service.
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 heating circuit. 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 coolant level
to stabilize.
Add 50/50 mixture to bring the coolant level back to FULL.
Turn all cab heater switches to HIGH in order to allow maximum coolant flow through heater core(s).
With the radiator pressure cap off:
• Operate the engine at LOW IDLE for 2 minutes.
• Turn off the engine and add coolant to bring the level back to FULL, using 50/50 mixture.
With the radiator pressure cap off:
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.
• Start the engine.
• Operate the engine at HIGH idle until the thermostats open.
Allow the engine to idle 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 pressure cap. Operate the engine until it reaches a temperature of 80°C [176°F] and check for coolant
leaks.
Check the coolant level again to make certain the system is full of coolant or that the coolant level has risen to the hot
level in the recovery/expansion tank in the system, if equipped.
Go to Figure 1 for a graphic explanation of the fill process.