FLUID- 3944779 - Caterpillar

Pressurized System: Hot coolant can cause serious burns. To open the cooling system filler cap, stop the engine and wait until the cooling system components are cool. Loosen the cooling system pressure cap slowly in order to relieve the pressure.
Climbing equipment may be required to access this service point. Refer to the Operation and Maintenance Manual, "Mounting and Dismounting"
topic for safety information.
Illustration 1 g00730268
A power module that is equipped with a horizontal radiator has two locations for the cooling system filler cap.
(1) Jacket water filler cap
(2) Separate circuit aftercooler filler cap Remove the access panel that is above the surge tank in order to check the coolant level.Check the coolant level when the engine is stopped and cool. Check the coolant level only after the engine has been stopped and the cooling system filler cap is cool enough to touch with your bare hand.Remove the cooling system filler caps slowly in order to relieve any pressure. Maintain the coolant within 1/4 to 1/3 from the top in the surge tank while the cooling system is cold.Add Coolant
Note: For the proper coolant mixture to use, see this Operation and Maintenance Manual, "Coolant Recommendations"
(Maintenance Section).
Stop the engine. Allow the engine to cool.
Remove the cooling system filler cap slowly in order to relieve any pressure. Pour the proper coolant mixture into the filler pipe.
Illustration 2 g00103639
Gaskets
Clean the cooling system filler cap. Inspect the gaskets of the cooling system filler cap. If the gaskets are damaged, replace the old cooling system filler cap with a new cooling system filler cap. Install the cooling system filler cap.
Start the engine. Inspect the cooling system for leaks.