CYLINDER 8T7775 - 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.
Replace the water temperature regulator on a regular basis in order to reduce the chance of unscheduled downtime and of problems with the cooling system.The water temperature regulator should be replaced after the cooling system has been cleaned. Replace the water temperature regulator while the cooling system is completely drained or while the cooling system coolant is drained to a level that is below the regulator housing.
Failure to replace the engine's thermostat 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 regulator housing.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the machine. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Caterpillar Tools and Shop Products Guide", for tools and supplies suitable to collect and contain fluids in Caterpillar machines.Dispose of all fluids according to local regulations and mandates.
Illustration 1 g00274556
The water temperature regulator is located on the left side of the machine at the back of the engine.
Open the engine hood. Pull the cable in order to open the engine access door on the left side of the machine.
Illustration 2 g00534849
Remove the four bolts and disconnect tube (1) from the regulator housing.
Illustration 3 g00521817
Remove the two bolts (2) and elbow (4) .
Remove three bolts (3) and regulator housing (5) from the engine cylinder head.
Illustration 4 g00521821
Remove the gasket, water temperature regulator (6), and the seal from regulator housing (5) .
Former thermostats may be used, if they meet test specifications and are not damaged or have excessive buildup of deposits.
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.
Install a new seal in the regulator housing. Install a new water temperature regulator and a new gasket in the regulator housing.Water temperature regulators can be reused under the following conditions:
The water temperature regulator meets test specifications.
The water temperature regulator is not damaged.
The water temperature regulator does not have excessive buildup of deposits.
Install the regulator housing (5) on the engine cylinder head. Install three bolts (3) .
Install elbow (4) and two bolts (2) .
Install tube (1) and the four bolts.
Fill the cooling system.ReferenceRefer to Operation and Maintenance Manual, "Cooling System Specifications" and to Operation and Maintenance Manual, "Refill Capacities".
Close the engine access door. Close the engine hood.