UENR0623-02 75 Cooling System Cooling System b. Clean the radiator and other components with hot water or steam at low pressure. Detergent in the water may also be used. Compressed air may be used to remove materials from the cooling system. Identify the cause of the restriction before you choose the method for cleaning. i05288851 Cooling System - Check c. Straighten any fins of the radiator if the fins are bent. Engine And Cooling System Heat Problems 5. Check the high idle of the engine. The engine may overheat if the high idle rpm is set too high. 1. The following conditions indicate that a heat problem exists. i03577882 Cooling System - Inspect a.
Hot coolant is released through the pressure cap during the normal operation of the engine. Hot coolant can also be released when the engine is stopped. This engine has a pressure type cooling system. A pressure type cooling system gives two advantages: b. Hot coolant is released from the coolant system but not through the pressure cap during normal operation of the engine. Hot coolant can also be released when the engine is stopped. The pressure type cooling system can operate safely at a higher temperature than the boiling point of water at different atmospheric pressure ranges. c. Coolant must be added frequently to the cooling system.
The coolant is not released through the pressure cap or through an outside leak. The pressure type cooling system prevents cavitation in the water pump. Cavitation is the sudden generation of low pressure bubbles in liquids by mechanical forces. The generation of an air or steam pocket is much more difficult in a pressure type cooling system. 2. If any of the conditions in Step 1 exist, perform the following procedures: a. Run the engine at medium idle, which is approximately 1200 rpm, for 3 minutes after the high idle shuts off. Running the engine at medium idle will allow the engine to cool before the engine is stopped.
Regular inspections of the cooling system should be made in order to identify problems before damage can occur. Visually inspect the cooling system before tests are made with the test equipment. Visual Inspection Of The Cooling System b. Inspect the poly v-belt for wear or for damage. If necessary, replace the poly v-belt. Refer to Operation and Maintenance Manual, “Alternator and Fan Belts - Replace” for the correct procedure. 1. Check the coolant level in the cooling system. 2. Look for leaks in the system. 3. Refer to “Visual Inspection Of The Cooling System” in order to determine if a leak exists in the cooling system. Note:
A small amount of coolant leakage across the surface of the water pump seals is normal. This leakage is required in order to provide lubrication for this type of seal. A hole is provided in the water pump housing in order to allow this coolant/seal lubricant to drain from the pump housing. Intermittent leakage of small amounts of coolant from this hole is not an indication of water pump seal failure. a. Refer to “Testing The Radiator And Cooling System For Leaks” procedures. 4. If the coolant does not flow through the radiator and through other components of the cooling system, perform the following procedures. 3.
Inspect the radiator for bent fins and other restriction to the flow of air through the radiator. a. Perform the “Testing The Water Temperature Regulator ” procedures. 4. Inspect the drive belt for the fan. 5. Inspect the blades of the fan for damage.