If by "bleed" you mean drain, disconnect the lower of the two hoses (do not confuse with the pipes from the AC evaporator) and drain the coolant into a bucket. If you are flushing the system (which you should if you are changing the coolant anyway), dont bother draining it, most of the coolant will flow out anyway, just do the coolant flush and fill from the radiator.
How do you bleed the heater after changing coolant in a 1992 4runner
Rarely do you find a bleeder valve on the heater. If there is one, it will be located on the highest point of the heater core connections from the engine. You can bleed the heater by turning it to hot and starting the engine. Use the bleeder valves on the engine or remove the radiator cap and run the engine until no more air bubbles are escaping. This should bleed all air from the heater core.
Bolt the heater core into place, with the four retaining bolts. Connect the water supply hoses. You might need to bleed one of the hoses to get the water flowing through the heater core.
You may have an air lock in the heater pipes some vehicles are fitted with bleed screws for this purpose.
you probably have air trapped in you heater core you shoud have it flushed/bleed to get the air out. the other possibility is a failing thermostat or water pump
First check the water level. Low level will not get to the heater core. Change the thermostat. If you recently changed the thermostat, bleed the coolant system.
you need to remove the two hoses from the engine compartment that lead to the heater core one is near the thermostat housing on the right side of the motor the other is on the left side going right to the water pump
Replace the radiator cap and be sure the coolant reservoir is kept full to the line, it will bleed itself.
Begin by removing the water supply hoses to your heater core. Remove the heater core retaining bolts. The heater core will come out. Reverse the process to install the new heater core.
the heater core, heater core hoses or heater control valve is leaking
Remove the water supply hoses from your 1985 Chevy heater core. Remove the heater core retaining bolts. The heater core will come out. Reverse the process to install your new heater core.
You can access the heater core from the passenger side kick plate in your 1964 Chevrolet Corvette. Remove the heater core water supply hoses. Remove the heater core retaining bolts. The heater core will come out.