The Ford Bronco was one of the first sport-utility vehicles: rough and versatile it was used for everything from pulling a trailer, to plowing snow, to off-road fun, etc. Many fourth generation – 1986 to 1991 – Broncos are still on the road today and a favorite of truck enthusiasts. Replacing the heater core in your Ford Bronco may look daunting, but it’s actually not too hard.
Remove heater hoses
- Drain about a quart of coolant from the radiator, so it won't leak all over your engine compartment and the ground.
- Loosen the two clamps, and remove the heater hoses attached to the core. If they're hard to get off, twist them with pliers -- or hose pliers if you have them.
Remove the glove compartment
- Remove all the gloves from your glove compartment -- or anything else that may be lurking in there.
- Hold the glove compartment and pull the pin out of the stop strap.
- Lower the glove box until you can slide it off the hinges.
- Remove the glove compartment and set it aside.
Remove the heater core cover
- Remove the clips holding the heater door cable and any wires that are attached to the cover.
- Remove the eight bolts securing the heater core cover to the heater box.
- Guide the cover over the core and remove it.
- Wipe any dirt, debris or coolant from the inside of the cover.
Remove the core
- Pull the heater core straight out of the heater box until the inlet and outlet tubes are clear of the holes in the firewall.
- Guide the heater core down until it is clear of the dashboard and heater box.
- Clean any dirt, debris and coolant from the inside of the heater box with a rag.
Install the replacement heater core
- Install the replacement heater core, guiding the inlet and outlet tubes carefully through the firewall. If possible have someone help you from the engine compartment side.
- Check the seal around the heater box to make sure it is properly in place.
Do not force the core if it gets stuck, you could end up cracking a solder joint and causing a leak.
Fill the cooling system
- Install one of the heater hoses and tighten the clamp.
- Place the other hose in a clean container.
- Slowly fill the radiator until coolant starts to come out of the hose.
- Install the hose and tighten the clamp.
- Start the engine with the radiator cap off and run it until it gets to operating temperature -- when you see the coolant circulating in the radiator.
- Install the radiator cap and let the engine run for about five minutes.
- Check for leaks.
- Install the heater core cover.
- Install the glove compartment.