How do you replace the heater core on a 66 F100 strandard heater? Any tricks? Thanks
Mark

 

The heater core is easy to change. However, BE VERY CAREFUL with the housing. It is fragile because it is made of 40 year old fiberglass, and is not strong originally to boot.

From under the dash:
Remove the cable lines, for heat and defrost, as applicable.
Remove the defrost hoses if easily accessible, or you can wait until you drop the box. You may need to replace the defrost hoses.
Disconnect the wiring.
You shouldn't need to remove the glove compartment.

From under the hood:
1. Remove the hoses.
2. Remove the 3 nuts holding the heaterbox assembly to the firewall.
At this point it is helpful to have someone to hold it in place, to keep it from falling down and fracturing.

From inside the truck:
Work the heater assembly out, being careful to not drop it.
Disconnect the wiring if necessary, and the defrost hoses as well.

Disassembly is simple.
There are (usually) several spring clips - remove these first.
Remove all the screws, and note the position of the interior components. It is simple, so it won't be hard to remember.
The heater core is held in place by rubber mounts; these will have most likely hardened over the years. They can be re-used if they don't disintegrate on removal.

Reassembly is the reverse; just be careful and it will take you about 2 hours at the most.

 

Yep, Banjopicker has it about right. I just did mine, no big deal. When you buy the core, up to a 79 will fit, in case the parts monkeys can't deal with your old truck. Also, be careful with the duct to the side wall. I haven't seen those available from the parts suppliers.

Dave

 

Duct to side wall is same as later years too, from what I have heard. However at $70, it still is best not to tear it up.