CASE AS 4992530 - Caterpillar

Pressurized system: Hot coolant can cause serious burn. To open cap, stop engine, wait until radiator is cool. Then loosen cap slowly to relieve the pressure.
Failure to replace the engine's thermostat on a regularly scheduled basis could cause severe engine damage.
Caterpillar engines incorporate a shunt design cooling system and require operating the engine with a thermostat installed.If the thermostat is installed wrong, it will cause the engine to overheat. Inspect gaskets before assembly and replace if worn or damaged.
Illustration 1 g02585476Replace the water temperature regulator in order to reduce the chance of problems with the cooling system.Replace the water temperature regulator and the seals while the cooling system is drained below the water temperature regulator housing.Note: If you are only replacing the water temperature regulator, drain the coolant to a level that is below the water temperature regulator housing.Reference: Refer to Disassembly and Assembly, RENR9214, "C11 and C13 Engines for Caterpillar Built Machines" for the correct procedure for replacing the water temperature regulator.