The correct coolant is any permanent, high quality ethylene glycol antifreeze mixed in a 50/50 concentration with water. This mixture gives the best combination of antifreeze and anti-boil characteristics within the engine.
See Figures 1, 2, 3, 4 and 5
It's best to check the coolant level when the engine is COLD. The radiator coolant level should be between the LOW and the FULL lines on the expansion tank when the engine is cold. If low, check for leakage and add coolant up to the FULL line but do not overfill.
Check the freeze protection rating of the antifreeze at least once a year or as necessary with a suitable antifreeze tester.
DRAIN & REFILL
See Figures 6 and 7
Completely draining and refilling the cooling system every two years at least 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.
- Drain the existing antifreeze and coolant. Open the radiator and engine drain petcocks. Some engines have two petcocks, but most are equipped with one. The easiest way to drain the system is to disconnect the bottom radiator hose, at the radiator outlet. Set the heater temperature controls to the full HOT position.
Before opening the radiator petcock, spray it with some penetrating lubricant.
- Close the petcock and tighten the drain plug(s) to 9 ft. lbs. (13 Nm) on 4 cyl. engines or 22 ft. lbs. (29 Nm) on 6 cyl. engines or reconnect the lower hose. Open the air relief plug (2VZ-FE) until you can see the hole.
- 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. It is recommended that you fill the system with the engine off, then start the engine and top off the levels once the engine is warmed up.
FLUSHING & CLEANING THE SYSTEM
Proceed with draining the system as outlined above. When the system has drained, reconnect any hoses close to the radiator draincock. Move the temperature control for the heater to its hottest position; this allows the heater core to be flushed as well. Using a garden hose or bucket, fill the radiator and allow the water to run out the engine drain cock. Continue until the water runs clear. Be sure to clean the expansion tank as well.
If the system is badly contaminated with rust or scale, you can use a commercial flushing solution to clean it out. Follow the manufacturer's instructions. Some causes of rust are air in the system, failure to change the coolant regularly, use of excessively hard or soft water, and/or failure to use the correct mix of antifreeze and water.
After the system has been flushed, continue with the refill procedures outlined above. Check the condition of the radiator cap and its gasket, replacing the radiator cap as necessary.
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.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 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.
CHECKING SYSTEM PROTECTION
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.