See Figures 1 and 2
Check the cooling system at the interval specified in the Maintenance Intervals chart at the end of this section.
Hose clamps should be tightened, and defective hoses replaced. Damp spots, or accumulations of rust or dye near hoses, water pump or other areas, indicate areas of possible leakage. Check the radiator cap for a worn or cracked gasket. If the cap doesn't seal properly, fluid will be lost and the engine will overheat. A worn cap should be replaced with a new one.
Periodically clean any debris from the radiator fins. Pick the large pieces off by hand. The smaller pieces can be washed away with water pressure from a hose.
Carefully straighten any bent radiator fins with a pair of needle nose pliers. Be careful-the fins are very soft. Don't move the fins back and forth too much. Straighten them once and try not to move them again.
The recommended fluid is a 50/50 mixture of ethylene glycol antifreeze and water for year round use. Use a good quality antifreeze with water pump lubricants, rust inhibitors and other corrosion inhibitors along with acid neutralizers. Use only antifreeze that is SAFE FOR USE WITH AN ALUMINUM RADIATOR.
See Figures 3, 4, 5 and 6
Coolant level should be checked at least once a month. With the engine cold, the coolant level should be even with the FULL mark on the coolant expansion tank. On some models, there is a coolant level dipstick.
DRAIN & REFILL
See Figures 7, 8, 9 and 10
- Remove the radiator cap.
- Position a suitable container under the radiator and open the draincock to drain the radiator.
- Clean the cooling system by flushing with clear water.
- Close the radiator draincock.
- Refill the system with a 50/50 mixture of antifreeze and water. Fill to the FULL mark on the reservoir and install the radiator cap only to the first stop.
- Start the engine and run it at fast idle until the upper radiator hose feels warm, indicating the thermostat has opened and coolant is flowing throughout the system.
- Stop the engine. Carefully remove the radiator cap and top off the radiator with the water/antifreeze mixture, if required.
- Install the radiator cap securely and fill the coolant reservoir to the FULL mark.
FLUSHING & CLEANING THE SYSTEM
Radiator and Engine Flush
- Drain the cooling system. Remove the thermostat and reinstall the thermostat housing.
- Disconnect the radiator overflow hose from the expansion tank and plug the end of the hose.
- Disconnect the intake manifold outlet hose from the manifold nipple and plug both the nipple and the hose.
- Disconnect the lower radiator hose from the radiator and position the hose to drain clear of the vehicle.
- Connect a high pressure hose to the radiator lower hose outlet. Back flush the radiator and engine until water runs clear out of the lower radiator hose. Turn the water on and off several times to pulse the flow and help loosen sludge deposits.
- When the system drains clear, unplug the radiator overflow hose. When water flows clear from the hose, reinstall the plug.
- Before reconnecting the cooling system hoses, disconnect all of the hoses installed for the radiator and engine back flush procedure. The heater coolant loop must be backflushed separately to prevent loosened sediment from lodging in the heater core.
- Install and clamp a garden hose female end fitting in the heater return hose, disconnected from the bypass nipple.
- Connect a garden hose to the hose fitting in the heater return hose and flush the heater core circuit until the drain water runs clear. Pulse the flow by turning the water on and off several times. Allow full flow for approximately 5 minutes.
- Shut off the flushing water and remove all adapters and plugs installed for the flushing operation. Reconnect all cooling system connections and tighten the hose clamps to 22-31 inch lbs. (2.5-3.5 Nm).
- Install the thermostat with a new housing gasket. Tighten the retaining nuts.
- Fill the cooling system and check for leaks.