FLUID RECOMMENDATION AND LEVEL CHECK
See Figures 1 and 2
The manufacturer recommends checking the radiator coolant every time you stop for gas. Dealing with the cooling system can be a dangerous matter unless the proper precautions are observed. It is best to check the coolant level in the radiator when the engine is cold. This is done by removing the radiator cap and seeing that the coolant is within 2 in. (51mm) of the bottom of the filler neck.
On 1976 and later models, the cooling system is equipped with an expansion tank. If coolant is visible above the MIN 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.
In the event that the coolant level must be checked when the engine is warm on a vehicle without the expansion tank, place a thick rag over the radiator cap and slowly turn the cap counterclockwise until it reaches the first detent. Allow all of the steam to escape. This will allow the pressure in the system to drop gradually, preventing an explosion of hot coolant. When the hissing noise stops, remove the cap the rest of the way.
If the coolant level is low, add equal amounts of antifreeze and clean water. On models without an expansion tank, add coolant through the radiator filler neck. Fill the expansion tank to the MAX level on vehicles with that system.
The radiator hoses, 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, swelling or any signs of incorrect seating in the radiator neck.
DRAIN, FLUSH AND REFILL
See Figures 3, 4, 5 and 6
Once every 24 months or 24,000 miles (38,000 km), the cooling system should be drained, thoroughly flushed and refilled. This should be done with the engine cold.
Completely draining and refilling the cooling system at least every two years will remove accumulated rust, scale and other deposits.
Use a good quality antifreeze with water pump lubricants, rust inhibitors and other corrosion inhibitors along with acid neutralizers. Use a permanent type coolant that meets the manufacturer's specifications found in your owner's handbook.
- Remove the radiator cap.
- There are two drain plugs in the cooling system: one at the bottom of the radiator and one at the rear of the driver's side of the engine. Both should be loosened to allow the coolant to drain.
- Turn on the heater control to its hottest position. This ensures that the heater core is flushed out completely. Flush the system thoroughly by refilling it with clean water; flush it through the radiator opening as it escapes from the two draincocks. Continue until the water running out is clear. Be sure to clean out the coolant recovery tank as well, if equipped.
- If the system is badly contaminated with rust or scale, use a commercial flushing solution to clear it; follow the manufacturer's instructions. Some causes of rust are air in the system, caused by a leaky radiator cap or an insufficiently filled or leaking system; failure to change the coolant regularly; use of excessively hard or soft water and failure to use a proper mix of antifreeze and water.
- When the system is clear, allow all the water to drain, then close the drain plugs. Fill the system, through the radiator neck, with a 50/50 mix of antifreeze and water.
- Start the engine and top off the radiator with the antifreeze and water mixture. If equipped with a coolant recovery tank, fill it half full with the coolant mix.
- Replace the radiator and coolant tank caps, then check for leaks. When the engine has reached normal operating temperatures, shut it off, allow it to cool, then top off the radiator or coolant tank as necessary.
See Figure 7
Most permanent antifreeze/coolant products have a colored dye added which makes the solution an excellent leak detector. When servicing the cooling system, check for leakage at:
Check the engine oil dipstick for signs of coolant in the engine oil. Also check the coolant in the radiator for signs of oil in the coolant. Investigate and correct any indication of coolant leakage.Check the Radiator Cap
See Figure 8
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 will overheat.
A worn cap should be replaced with a new one.
See Figure 9
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 needlenose 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.
CHECKING SYSTEM PROTECTION
See Figure 10
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.