gsimon767

Car is a 75 convertible with AC.

I am trying to replace the heater core. The dash is removed. The four heater box attaching bolts are removed. The temperature door cable is removed. The passenger side lower brace is removed. The heater box appears to be loose but will not come out.It appears to be hanging up on something. See the video. What am I missing. I thought the three bolts and one stud and nut are all that holds the heater box to the firewall.

Also I cannot remove the center distribution duct. It is hitting the vacuum valve on the drivers side of the heater box. Can the duct be removed without removing the heater box or the drivers side dash?

Paul L

Did you loosen off this stud on the engine side?

gsimon767

Yes. It was the first one I removed. The three bolts on the inside are also removed.

mrvette

Been some 20 years since I did this on my '72, but AS I RECALL, there is a bolt down lo on the engine side, and when I put mine back together, I somehow reversed the bolt so it was from inside, to keep it simple....

I have the heater core outta the circuit, but a new one here ready to go, all I need to do is get off my lazy ***......

Paul L

I don't wish to sound silly but you did take the heater hoses off?

SWO vette

I did this a while back on my 72. You have to,hold,your mouth just right to,get the center distribution duct out and use a few choice words. The stud on mine was down low access from the bottom if I remember right. The nut was gone on mine so it wasn't a issue. I look for some photos if I can find them I'll post them. It was just time consuming. When you go back together make sure you have all the vacuum lines hooked up especially the one in back. Don't ask me how I know.

gsimon767

Not silly at all. Any idea is appreciated. I did remove the hoses but have forgotten things in the past. I am really puzzled why it is sticking.

gsimon767

By slightly separating the middle heater section from the heater core section there is just enough room to twist and fiddle the the core section out. The shape of the heater core tubes in an air conditioned car makes for a tight squeeze. Now that I have done this for the first time I am sure it would be easier the next time. Experience counts.

kdf1986

Hello
I am too late to post to help you, but you did it the same way I did.
I could not get the heater box out of my 73 A/C vette. I must have crawled under the 10 times looking as to why it would not come out.

Due to the shape of the tubes going down, it was be twisted and angled just right to get them to slide out. Putting them in was just as difficult. I couldnt figure out what they were hitting on. They have to be angled to get them in.

and dont forget the vacuum hose that hooks up to the inside of the box when you get it all buttoned up. I had to dig through the AIM catalog to find out the black with pink stripe ( I think I remember that) goes through the box, into the vac. unit on the inside.

kdf