NOTE: Never use a sealing additive to stop leaks in the coolant system . This can result in coolant system plugging
and inadequate coolant flow, causing the engine to overheat.
The engine coolant level must be checked daily.
NOTE: In the event of a water pump or EGA cooler failure, it is recommended that coolant level switches be checked
for operation. Use the following procedure in the , ISB, ISC, ISL, ISDe, and QSB3.3 CM2150, Electron ic Control
System, Troubleshooting and Repair Manual, Bulletin 4021570. Refer to Procedure 019-017 in Section 19.
On applications that use a coolant recovery system, check to make sure the coolant is at the appropriate level in the
coolant recovery tank for the engine temperature.
Many coolant recovery/expansion tanks, also called “top tanks”, have sight glasses {1) or are made of a clear
material (not shown) to aid in checking the coolant level (2) without removing the radiator cap.
It is important to understand the impact of temperature on the expansion of the coolant. Most “top tanks” do not have a provision for a ” FULL HOT” coolant level. Filling the “top tank” while hot will result in a low operating level once the system has cooled.
Fill the cooling system with coolant to the bottom of the fill neck in the radiator fill or recovery/expansion tank.
NOTE: Some radiators have two fill necks, both of which must be filled when the cooling system is drained.
