DIODE 2089270 - Caterpillar

Personal injury can result from hot coolant, steam and alkali.At operating temperature, engine coolant is hot and under pressure. The radiator and all lines to heaters or the engine contain hot coolant or steam. Any contact can cause severe burns.Remove cooling system pressure cap slowly to relieve pressure only when engine is stopped and cooling system pressure cap is cool enough to touch with your bare hand.Do not attempt to tighten hose connections when the coolant is hot, the hose can come off causing burns.Cooling System Coolant Additive contains alkali. Avoid contact with skin and eyes.
Note: The thermostats should be replaced after the cooling system has been cleaned. Replace the thermostats while the cooling system is completely drained or while the cooling system coolant is drained to a level that is below the thermostat housing.
Failure to replace the engine's thermostat on a regularly scheduled basis could cause severe engine damage.
Replace the four thermostats on a regular basis in order to reduce the chance of unscheduled downtime and of problems with the cooling system.
Park the machine on a level surface. Engage the parking brake and stop the engine.
Illustration 1 g01159005
(1) Filler cap for the aftercooler cooling system
(2) Filler cap for the jacket water cooling system
Remove filler caps (1) and (2) slowly in order to relieve the pressure.
Illustration 2 g01172817Note: Make sure that the coolant level is below the thermostat housings.
Disconnect the hose assemblies from thermostat housing assemblies (3).
Remove the thermostat housing assemblies.
Remove the gasket, the thermostat, and the seal from the thermostat housing assembly.
Former thermostats may be used, if they meet test specifications and are not damaged or have excessive buildup or deposits.
Since Caterpillar engines incorporate a shunt design cooling system, it is mandatory to always operate the engine with a thermostat.Depending on load, failure to operate with a thermostat could result in either an overheating or an overcooling condition.
If the thermostat is installed incorrectly, it will cause the engine to overheat.
Install a new seal in the thermostat housing. Install a new thermostat and a new gasket. Repeat Steps 5 and 6 for the three remaining thermostats.
Install the thermostat housing assemblies on the engine cylinder head. Connect the hose assemblies to the thermostat housing assemblies.
Tighten the hose clamps.