hotrod351

well seems like its time to replace my heater core. i have a 1970 mustang with ac. any one know how hard this is to do. where do i start.

Nabster

The heater box in the 69/70 isn't a fun thing to deal with. I just had a garage with experience replace mine for me.

hotrod351

i know i can do it, ive done everything else to it. just wondered if there was a half easy way to get the core out or do i need to remove the whole thing, including disconnecting the ac evaporator. i thought that maybe i could separate the box and pull the heater core out then replace it and put the box back together.

REAVER117

I don't have AC, but to get my heater core out I had to drain the radiator then remove the entire dash, and a couple bolts in the engine bay. It wasn't hard, just a lot of work.

BigIron22

your going to have to pull the heater box completely out. it is a pain but not nearly as bad as newer cars. I've had mine out and apart 3 times. i keep breaking the solder joint on the brass tube going into the heater core body. the heater hoses don't seem to have enough room by the valve covers and when the engine rocks it pushes on the hoses busting the solder joint.

hotrod351

thats what i figured. well i must of gotten lucky because it doesnt smoke. its my wifes daily driver and she told me when she started the heater three weeks ago, first time since last winter, it blew smoke out of the vents. i went out and started it and no smoke at all. started the car three times today and nothing came out of the vents. im curious though, it seems that the blower motor must be inside the car. i looked under the hood and cant see the motor sticking out the firewall. wonder how hard that is to change. does it hang down or stick straight back towards the rear seat.

REAVER117

Maybe 70's are different but my blower motor is in my engine bay. It's on the passenger side and it looks like a coke can is sticking out of the firewall.

BigIron22

i'm trying to think if the blower goes through the firewall on a/c cars. i don't think it does. if it is on inside you should be able to see it by looking up behind the glove box. i'm at work and can't remember the exact spot of the blower. Also your heater core may have just been dusty from not having airflow all summer. usually when the heater core ruptures it will fog the windshield just above the defrost ducts when the car is off.

Nabster

The blower on my AC car is under the dash, not in the engine compartment.