At least once every 2 years, the engine cooling system should be inspected, flushed, and refilled with fresh coolant. If the coolant is left in the system too long, it loses its ability to prevent rust and corrosion. If the coolant has been diluted with too much water, it won't protect against freezing.
The radiator cap should be examined for signs of age or deterioration. Fan belts should be inspected and, if necessary, adjusted to the proper tension (please refer to Belt Adjustment in this section).
Hose clamps should be tightened, and soft or cracked hoses replaced. Damp spots, or accumulations of rust or dye near hoses, the water pump or other areas, indicate possible leakage. This must be corrected before filling the system with fresh coolant.Checking The Radiator Cap
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 in the form of steam and the engine will overheat. If necessary, replace the cap with a new one.
Periodically clean any debris (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.
Coolant used is normally a 50/50 mixture of ethylene glycol and water which can be used year round. Always use a good quality antifreeze with water pump lubricants, rust and other corrosion inhibitors, and acid neutralizers. Also available is another type of antifreeze, propylene glycol, which is non-toxic. Keep in mind that should you decide to use a propylene glycol antifreeze, you should follow the antifreeze manufacturer's instructions closely. Do not mix ethylene and propylene glycol together, as the benefits of the non-toxic propylene glycol would be lost. In the event you decide to change to propylene glycol, make sure to completely flush the cooling system of all ethylene glycol traces.
FLUSHING & CLEANING THE SYSTEM
- Remove the radiator cap. Drain the existing coolant by opening the radiator draincock, or by disconnecting the bottom radiator hose at the radiator outlet.
- Close the draincock or re-connect the lower hose and fill the system with water.
- Add a can of quality radiator flush.
- Idle the engine until the upper radiator hose gets hot.
- Drain the system again.
- Repeat this process until the drained water is clear and free of scale.
- Close all draincocks and connect all the hoses.
- Flush the recovery reservoir with water and leave empty.
- Determine the capacity of your cooling system, then add a 50/50 mix of quality antifreeze and water to provide the desired protection.
- Run the engine to operating temperature.
- Stop the engine and check the coolant level.
- Check the level of protection with an antifreeze tester, replace the cap and check for leaks.