How to Install a 1986 Ford Aerostar Heater Core

Signs that indicate the need to replace a heater core include coolant in the floor area of the Ford Aerostar, and greasy film at the bottom of the windshield. If not replaced, windows will begin to fog and floor boards will begin to rust, which could lead to overheating due to loss of antifreeze. Replacing the heater core in the Ford Aerostar takes a couple of tools and a few of hours to complete.

Instructions

Replacing the Heater Core

1

Open the valve at the bottom of the radiator by removing the radiator cap to drain the cooling system. Always drain the coolant into a container that can be sealed and reused if its not several years old. When draining the coolant, remember animals are attracted to antifreeze, and will drink any that is left in an open container or on the ground. This will make pets sick and could be fatal.

2

Disconnect the heater hoses from the heater core using tool T85T-18539-AH, to compress the couplers. The T85T-18539-AH tool or a comparable tool is available at most auto-parts stores; some auto parts stores offer the borrowing or rental of tools. The heater hoses connect to the heater core tubes on the fire wall passenger side of the engine compartment. Plug the heater hoses with small pieces of a rag to stop any coolant loss while removing the heater core.

3

While working in the passenger compartment, lay an old towel on the floorboard in case any coolant spills. Remove the six screws holding the heater core access door to the blower assembly; remove the access door. Depress the retainer clips at the top of the heater core and pull the heater core toward the bottom of the passenger seat, removing it from the blower assembly.

4

Remove the new heater core from the manufacturers box. Make sure it matches the old one. Position the new heater core caully into the blower assembly, snapping the top of the heater core into the retainer clips. Install the heater core access door to the blower assembly with the six screws that were removed.

5

Reconnect the heater hoses to the new heater core tubes inside the engine compartment. Push on the heater hose coupler until it locks. Tighten the drain plug at the bottom of the radiator. Fill the radiator with coolant. Start the Ford Aerostar, leaving the radiator cap off and turning the heater on high. Watch for coolant level to drop in the radiator, then turn the ignition off. Top off with coolant and replace the radiator cap.

6

This is a good time to check for leaks. Start the vehicle and let it warm up with the heater on high. While waiting for the vehicle to warm up, drain the coolant from the old heater core into a suitable container. Check for leaks at the hose connections and under the dash on the passenger side. If there are no leaks, discard the old heater core and towel from the passenger floorboard.