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: This procedure pertains to Caterpillar Diesel Engine Antifreeze/Coolant (DEAC) only. This does not pertain to machines that are shipped from the factory with Extended Life Coolant (ELC). This does not pertain to machines that are maintained with Extended Life Coolant (ELC).
NOTICE |
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Do not change the coolant until you read and understand the material in the Cooling System Specifications section. |
NOTICE |
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Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. 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 on Caterpillar products. Dispose of all fluids according to local regulations and mandates. |
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 engine compartment.
- Slowly remove the cooling system pressure cap in order to relieve pressure.
- Open the drain valve that is under the radiator. Allow the coolant to drain into a suitable container.
- Close the drain valve. 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.
- Add the coolant solution. Refer to Operation and Maintenance Manual, "Refill Capacities".
Note: If you are using Caterpillar Long Life Coolant that contains some additive, do not add any supplemental coolant additive at this time. Also, do not change the coolant conditioner element if you are using Caterpillar Long Life Coolant that contains some additive.
- Take off 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 level of the coolant to 1 cm of the bottom of the fill pipe .
- Install the cooling system pressure cap.
- Stop the engine.
- Close the engine compartment.