Q: How to replace a heater core in a Chevrolet Metro?
A: Just like before, remove the negative cable from the battery. Drain the cooling system. Unplug the heater hoses at the firewall in the engine bay. Remove just the instrument cluster. Get rid of any heater controls. You must then ensure that you note where these cable clamps are placed on cables to guarantee that they can be properly adjusted after installation is over. Remove instrument panel assembly. At this point, you need to label and unplug air ducts, wiring and controls still attached to the heater housing. Unbolt heater assembly from fire wall. Unscrew and unclip two halves of heater assembly apart . Remove old core and put in new one. After this take back both parts of heater unit together and check if control flaps operate well. Any binding parts should be repaired before installing them back into place. Put back other parts in reverse order of removal and refill cooling system reconnect batteries start engine running it for few minutes checking leaks and proper working of whole system.