ENGINE AR-COMPLETE 1929523 - Caterpillar

Failure to replace the engine's water temperature regulator on a regularly scheduled basis could cause severe engine damage.
Note: If you are only replacing the water temperature regulator, drain the cooling system coolant to a level that is below the water temperature regulator housing.
Open the engine compartment.
Illustration 1 g01800413
At operating temperature, the engine coolant is hot and under pressure.Steam can cause personal injury.Check the coolant level only after the engine has been stopped and the fill cap is cool enough to touch with your bare hand.Remove the fill cap slowly to relieve pressure.Cooling system conditioner contains alkali. Avoid contact with the skin and eyes to prevent personal injury.
Remove the cooling system pressure cap in order to relieve the pressure in the cooling system.
Illustration 2 g01800454
Loosen hose clamp (2) and remove hose (1) from water temperature regulator housing (3).
Remove bolts (4) from water temperature regulator housing (3) and remove water temperature regulator housing (3).
Remove the gasket and remove the water temperature regulator from the water temperature regulator housing. Make a note of the orientation of the old regulator.
The water temperature regulators may be reused if the water temperature regulators are within test specifications, are not damaged, and do not have excessive buildup of deposits.
Since Caterpillar engines incorporate a shunt design cooling system, it is mandatory to always operate the engine with a water temperature regulator.Depending on load, failure to operate with a water temperature regulator could result in either an overheating or an overcooling condition.
If the water temperature regulator is installed incorrectly, it will cause the engine to overheat.
Install a new water temperature regulator. Orient the regulator in the same manner as the old regulator. Install a new gasket. Install the water temperature regulator housing.
Install the water temperature regulator housing and the hose. Tighten the hose clamp.
Illustration 3 g01796033
Add the cooling system coolant. Maintain the level of the coolant between the "MAX" and "MIN" marks on the shunt tank.
Inspect cooling system pressure cap and the gasket for damage. Replace the pressure cap if the pressure cap or the gasket are damaged.
Install the cooling system pressure cap.
Close the engine compartment.