How to Replace a Radiator in a Mitsubishi Eclipse

Disconnect the negative battery cable before you proceed. Then, locate the drain plug on the bottom of the radiator and drain the engine coolant into a resealable container. Removing the radiator cap will help the radiator to drain faster.

Remove the overflow tank and hose, and disconnect both upper and lower radiator hoses. Use a pencil to mark the upper radiator hose to be sure that you can reinstall it correctly. If your Eclipse is equipped with an automatic transmission, detach the oil cooler hoses. Mark the hose with a pencil before you remove it to help with the reinstallation process.

Remove the upper radiator supports and pull the radiator assembly out of the engine compartment.

Transfer any remaining attachments from the old radiator to the new radiator, and install the radiator assembly in the engine compartment. Tighten the bolts according to specifications.

Reconnect the automatic transmission lines, if applicable. Tighten the bracket bolt according to specifications and reconnect the upper radiator hose and lower radiator hose.

Put the radiator tank into position and tighten the bolts according to specifications. Reconnect the overflow hose and connect the negative battery cable.

Fill the radiator with a blend of half engine coolant and half distilled water. Start the engine, let it run for several minutes with the radiator cap on very loosely. Turn the engine off and top off the engine coolant blend. Put the radiator cap on securely.