The heater hoses located in your Mitsubishi Eclipse direct coolant from the heater core to the inside of the vehicle to keep it warm. Heater hoses deteriorate after several years, so you'll need to remove and replace them occasionally. Here's how to check, remove and replace heater hoses.
Turn off the engine, allow it to cool and locate the heater hoses on the Eclipse. On most Eclipse models, the heater hoses connect to heater tubes at the firewall.
Examine the heater hoses for bulges or cracks. Look for mushy or brittle rubber and loose clamps. Telltale bulges in the middle of heater hoses indicate that hoses may rupture, so you need to replace them immediately.
Eliminate the coolant in the radiator. Place a drain pan underneath the radiator and loosen the petcock located at the bottom of the radiator. Put the old coolant in a sealed container and dispose of it according to your local municipality regulations.
Remove the clamps that connect the heater hoses to the heating tubes. Take a heater hose removal tool, a screwdriver or pliers to do this. Use a utility knife to cut the old hose from the end of the hose to just above the heater tube. Twist or pull the Eclipse's heater hoses to loosen and lift them out of the heater compartment.
Ensure that the clamp fittings are clean by wiping them with a multipurpose cleaning solution. Close the gaskets with a sealer. Put on the new heater hoses by sliding the clamps along the hose to the end. Be sure the clamps fit snuggly but not too tight as they may crack the new heater hoses.
Put fresh coolant in the radiator. Turn the engine on and check for leaks. If you see leaks, check the clamp and heater hose connections and adjust as necessary. Once the system is leak free, close the hood of the Eclipse.
