DEX-COOL® is an ethylene-glycol coolant that was developed to last for 150,000 miles (240,000 km), or 5 years, whichever occurs first. It is recommended that only DEX-COOL® be used when coolant is added or changed. A 50/50 mixture of this ethylene-glycol coolant and water should be used, providing freezing protection down to -34°F. (-37°C), boiling protection to 265°F (129°C), and rust and corrosion protection for the system. A solution stronger than 70% antifreeze is not recommended and pure antifreeze will freeze at only -8 ° F (-17°C).
- Remove the radiator pressure cap.
- Position a clean container under the radiator and/or engine draincock or plug, then open the drain and allow the cooling system to drain to an appropriate level. For some upper hoses, only a little coolant must be drained. To remove hoses positioned lower on the engine, such as a lower radiator hose, the entire cooling system must be emptied.
- Loosen the hose clamps at each end of the hose requiring replacement. Clamps are usually either of the spring tension type (which require pliers to squeeze the tabs and loosen) or of the screw tension type (which require screw or hex drivers to loosen). Pull the clamps back on the hose away from the connection.
- Twist, pull and slide the hose off the fitting, taking care not to damage the neck of the component from which the hose is being removed.
- Clean both hose mounting connections. Inspect the condition of the hose clamps and replace them, if necessary.
- Dip the ends of the new hose into clean engine coolant to ease installation.
- Slide the clamps over the replacement hose, then slide the hose ends over the connections into position.
- Position and secure the clamps at least 1 / 4 in. (6.35mm) from the ends of the hose. Make sure they are located beyond the raised bead of the connector.
- Close the radiator or engine drains and properly refill the cooling system with the clean drained engine coolant or a suitable mixture of ethylene glycol coolant and water.
- If available, install a pressure tester and check for leaks. If a pressure tester is not available, run the engine until normal operating temperature is reached (allowing the system to naturally pressurize), then check for leaks.