The cooling system is a vital part of an engine's ability to operate efficiently and to last a long time. Periodically clean any debris such as leaves, paper, insects, etc., 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 wiggle the fins back and forth too much. Straighten them once and try not to move them again.
A 50/50 mix of coolant concentrate and water will usually provide protection to -35°F (-37°C). Freeze protection may be checked by using a cooling system hydrometer. Inexpensive hydrometers (floating ball types) may be obtained from a local department store (automotive section) or an auto supply store. Follow the directions packaged with the coolant hydrometer when checking protection.
When additional coolant is required to maintain the proper level, always add a 50/50 mixture of ethylene glycol antifreeze/coolant and water. Do NOT use an alcohol type.
It is best to check the coolant level in the radiator when the engine is cold. This is done by checking the expansion tank. If coolant is visible above the low mark on the tank, the level is satisfactory. Always be certain that the filler caps on both the radiator and the reservoir are tightly closed.
It's a good idea to check the coolant every time that you stop for fuel. If the coolant level is low, add equal amount of ethylene glycol-based antifreeze and clean water. On models without an expansion tank, add coolant through the radiator filler neck. Fill the expansion tank to the full level.
Avoid using water that is known to have a high alkaline content or is very hard, except in emergency situations. Drain and flush the cooling system as soon as possible after using such water.
The radiator hoses and clamps and the radiator cap should be checked at the same time as the coolant level. Hoses which are brittle, cracked, or swollen should be replaced. Clamps should be checked for tightness (screwdriver tight only! Do NOT allow the clamp to cut into the hose or crush the fitting). The radiator cap gasket should be checked for any obvious tears, cracks or swelling, or any signs of incorrect seating in the radiator neck.
Most permanent antifreeze/coolant have a colored dye added which makes the solution an excellent leak detector. When servicing the cooling system, check for leakage at:
Investigate and correct any indication of coolant leakage. Also, while you are checking the coolant level, check the radiator cap for a worn or cracked gasket. If the cap doesn't seal properly, fluid will be lost and the engine can overheat. A worn cap should be replaced with a new one.
DRAIN, FLUSH AND REFILL
Completely draining and refilling the cooling system every two years at least will remove accumulated rust, scale and other deposits.
- Drain the existing antifreeze and coolant. Open the radiator and engine drain petcocks. Set the heater temperature controls to the full hot position.
- Close the petcock and tighten the drain plug(s) to 9 ft. lbs. (13 Nm).
- Add a can of quality radiator flush. Be sure the flush is safe to use in engines having aluminum components.
- Idle the engine until the upper radiator hose gets hot. Race it 2 or 3 times and then shut it off. Let the engine cool down.
- Drain the system again.
- Repeat this process until the drained water is clear and free of scale.
- Close all petcocks and connect all the hoses.
- If equipped with a coolant recovery system, flush the reservoir with water and leave empty.
- Determine the capacity of your cooling system (see Capacities specifications). Add a 50/50 mix of quality antifreeze (ethylene glycol) and water to provide the desired protection. Add through the radiator filler neck until full and then fill the expansion tank to the Full line.