MAINTENANCE 24.9 EVERY 2000 HOURS SERVICE Maintenance for every 50, 100, 250, 500 and 1000 hours should be carried out at the same time. 24.9.1 COOLING SYSTEM, REPLACE COOLANT AND FLUSH THE SYSTEM WARNING If the engine was just running, then the coolant could be hot and cause personal injury. Allow the engine to cool before draining water. Never remove the radiator cap when the engine is at operating temperature. At operating temperature, the coolant is under pressure. Steam blowing up from the radiator could cause personal injury. Allow the engine to cool until the radiator filler cap is cool enough to touch with your hand. Remove the filler cap slowly to allow pressure to be relieved.
GENERAL The cooling system operates under pressure which is controlled by the pressure relief valve in the radiator cap. The belt-driven water pump circulates the coolant through the engine block, cylinder heads, radiator and engine oil cooler. A thermostat controls circulation by routing coolant flow around the radiator until the engine reaches operating temperature. Proper cooling is possible only when the system is sealed, the radiator cap gasket is in good condition, the pressure relief valve and thermostats are operating properly. The system must be free of coolant and air flow restrictions and the system filled to the proper level. The engine coolant is important to long engine life.
The following information provides recommendations for selecting the engine coolant, maintaining the coolant inhibitors and servicing the cooling system. The system operates successfully with a water/antifreeze mixture or inhibited/conditioned water as the coolant. Water by itself allows rust, scale deposits, and corrosion to occur. After 2,000 hours or one year of operation, whichever comes first, the cooling system should be drained, flushed, and refilled and the corrosion resistor filter replaced as described in this section. For complete coolant specifications see "20.3 COOLANT SPECIFICATIONS" on page 3-14. REMARKS:
Always replace the coolant corrosion resistor filter after cleaning and flushing the cooling system and installing new coolant. See "24.7 EVERY 500 HOURS SERVICE" on page 3-54. RADIATOR CAP GENERAL INFORMATION 3-65 WA320-3MC