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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. |
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If the coolant is dirty or if you observe any foaming in the cooling system, drain the coolant before the recommended interval.
It is important to replace the thermostat in order to avoid any unexpected failure of the thermostat. This is a good preventive maintenance practice that reduces the chances of unscheduled downtime. Failure to replace the thermostat on a regularly scheduled basis could cause severe engine damage.
Note: If you are only replacing the thermostat, drain the coolant from the cooling system so that the level of the coolant is below the thermostat housing.
Always operate Caterpillar engines with a thermostat because these engines have a shunt design cooling system.
Note: Thermostats can be reused if the thermostats meet certain test specifications. The tested thermostats must not be damaged and the tested thermostats must not have an excessive buildup of deposits.
- Stop the engine and allow the engine to cool.
- Open the cover. Slowly remove the cooling system pressure cap in order to relieve pressure.
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| Illustration 1 | g00108134 |
- Remove the drain plug (1). The drain plug (1) is located on the water line at the lower left side of the engine. Open the drain valve (2). The drain valve is located under the radiator. Allow the coolant to drain into a suitable container.
Note: Discard any drained fluids according to local regulations.
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| Illustration 2 | g00117934 |
- Close the drain valve. Clean the drain plug and install the drain plug. Fill the cooling system with clean water and with a 6 to 10% concentration of cooling system cleaner.
- Start the engine. Run the engine for 90 minutes.
- Stop the engine. Drain the cleaning solution.
- Flush the cooling system with water until the draining water is transparent.
- Close the drain valve and install the drain plug.
- Add the coolant solution. Refer to Operation and Maintenance Manual, "Refill Capacities".
- Remove the cooling system pressure cap. Start the engine and run the engine. Leave the cap off until the thermostat opens and the coolant level stabilizes.
- Maintain the coolant level within 13 mm (.5 inch) of the bottom of the filler tube.
- Install the cooling system pressure cap. Close the cover.
- Stop the engine.