Challenger 65E, Challenger 75E, Challenger 85E and Challenger 95E Agricultural Tractors Caterpillar

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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.

See the appropriate topics in your machine's Operation and Maintenance Manual for all cooling system requirements.

Change the engine coolant more frequently if you find any of the following conditions:

• The cooling system is heavily contaminated.

• The engine overheats.

• You observe foaming in the radiator.

• The oil cooler has failed and oil is in the coolant.

• Fuel has contaminated the cooling system.

• The cooling system contains non-Caterpillar products.

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.

1. Park the machine on a hard, level surface. Allow the engine to cool and allow the radiator to cool.

2. Raise the hood in order to access the radiator.

   Note: See Operation and Maintenance Manual, "Engine Compartment Hood - Raise/Lower".

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Illustration 1	g00387093

3. Slowly loosen the filler cap in order to relieve the pressure. Remove the filler cap.

4. Inspect the filler cap gasket. Replace the filler cap if the gasket is damaged.

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5. Attach a hose to the nipple on the drain valve. Open the drain valve that is under the radiator. Allow the coolant to drain into a suitable container.

   Note: Always discard drained fluids according to local regulations.

6. Close the drain valve. Fill the cooling system with clean water and with a 6 to 10% concentration of cooling system cleaner. Install the filler cap.

7. Start the engine. Run the engine for 90 minutes.

8. Stop the engine. Drain the cleaning solution.

9. Flush the cooling system with water until the draining water is transparent. Fully drain the cooling system.

10. Close the drain valve.

11. Add the coolant solution. See Operation and Maintenance Manual, "Refill Capacities".

    Note: At this time, do not add any supplemental coolant additive if you are using Caterpillar Extended Life Coolant that contains some additive.

12. Start the engine. Operate the engine until the coolant reaches the normal operating temperature and until the coolant level stabilizes.

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Illustration 3	g00388695

13. Coolant should be visible in the coolant recovery bottle. As needed, add coolant.

14. Install the filler cap.

15. Stop the engine.

Clean Cooling System Relief Valve

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Clean the relief valve or replace the relief valve if the system overheats or loss of coolant is observed.

1. Remove the radiator cap slowly in order to relieve the pressure.

2. Inspect the relief valve and the gasket in the radiator cap. Replace the radiator cap, if the valve or the gasket are worn or damaged.