It's in the heater core housing.
Not practical to try to fix a heater core. Replace it with a new one.
To change the heater core in a 1986 Toyota Supra, first disconnect the battery and drain the coolant. Remove the dashboard and climate control assembly to access the heater core housing. Disconnect the heater core hoses from the firewall, then unbolt and remove the heater core itself. Install the new heater core, reassemble the housing, dashboard, and reconnect the hoses, ensuring to refill the coolant before testing the system.
Talk2DIY Automotive - 1986 Tires and Changing Heater Core was released on: USA: 14 August 2004
Replace the heater core. It is leaking.
osmobile delta88
If that made sense i'd answer it
Low coolant? Thermostat not opening? Control cable not working? Plugged heater core? Heater core "airbound"? Low coolant? Thermostat not opening? Control cable not working? Plugged heater core? Heater core "airbound"?
To change out the heater-core in a 1986 F-150, you must access the old heater-core through the glove box. You must remove the glove box by removing the screws that hold it in. Once this is accomplished, you must loosen the clamps on the hoses that are connected to the old heater-core unit. Then remove the hoses from the old heater-core and slide the old heater-core out through the opening where the glove box use to be. Install the new one using these instructions in reverse! Presto...installed! Mechanic Man
By the firewall, up and under the dash.
Loosen the dash and pull out the complete heater box after you have disconnected the heater hose from the firewall...........
Generally, the upper heater hose leads to the water pump.
just under $40.00 @ Advance auto