Question: Do I really need to disasemble the whole dash?

[Bolisk]

In the very near future, I'm going to be replacing the heater core in my 1970 vette. I do not have AC.

All the tech articles that I have seen show what is needed if your have an AC car. I've heard it's easier / less involved if I don't have AC.

So, I was wondering if I have to still dismantle the entire dash (i.e. both dash pads, and the center gague cluster), or if I can do the entire job by just removing the right lower dash pad?

Also, did my car have a water cut-off valvue in the engine bay. . .that would keep hot water from going to the heater core? Or was that just in AC cars? I though I just install to hoses from the water pump to the heater core. . .without any breaks in the line. (Note: my heater core is not hooked up currently.

-JR

 

[paul67]

I have done it from the front/firewall on a couple of occasions. Here's my write-up from the year 2000.

http://www.corvettefaq.com/c3/heatercore.html

 

[Bolisk]

hmmm....

You know. . .I was wondering if I could do that. . .but never seen anyone say it was possible. Anyone else have success doing this on a earlier c3? Or is the '79 and '70 similar enough?

 

[paul67]

I did my 1974 (with A/C) in June. I do not wish that job on anyone.

As to 1970 and 1979, I really do not know. The core is common 1968-79 but the firewall configuration may differ. Perhaps others will have a better idea.

 

[gmjunkie]

hmmm....

You know. . .I was wondering if I could do that. . .but never seen anyone say it was possible. Anyone else have success doing this on a earlier c3? Or is the '79 and '70 similar enough?

You won't do it on a AC car that way!!

I did my 1974 (with A/C) in June. I do not wish that job on anyone.

As to 1970 and 1979, I really do not know. The core is common 1968-79 but the firewall configuration may differ. Perhaps others will have a better idea.

68-79 are purdy much the same,and your way is the only way to do it on a AC car!!

 

[KANE]

That is a job- isn't it!

I think everyone who removes their heater core ends up taking pictures because it is such an achievement.
:L

I pulled the heater core out of my first C3- a 1978. I didn't have to take that dash out. I did loosen the side by the door, removed the glove box (in your case- map pocket), and the side boards along the console.

Essentially, I loosened everything I could so that I could rotate and twist the heater core and assembly out from under the dash. It can be done. Give yourself about 5 hours though- it isn't a fast affair!

 

[Bolisk]

So, as mentioned before, my car doesn't have the heater core hooked up. And, in the summer that don't bother me in the slightest. However, in the fall / early spring. . .it is mighty chilly in the car. . .so getting this done is important to me.

However, I've heard many people complaing that the heater core add's a tremendous amount of heat to the cabin, even with the heater off. Is this true? My car does not run hot . . . like many C3's. Still, if there is a lot of heat coming from the box, has anyone experiemented with wraping the box with heat shield?

 

[paul67]

So, as mentioned before, my car doesn't have the heater core hooked up. And, in the summer that don't bother me in the slightest. However, in the fall / early spring. . .it is mighty chilly in the car. . .so getting this done is important to me.

However, I've heard many people complaing that the heater core add's a tremendous amount of heat to the cabin, even with the heater off. Is this true? My car does not run hot . . . like many C3's. Still, if there is a lot of heat coming from the box, has anyone experiemented with wraping the box with heat shield?

It's easier to spend $10.00 at Home Depot and control the coolant flow manually.

 

[Bolisk]

Did you put the valvue on the return line, or the input line?

 

[paul67]

I can't recall which is input and which is return. It's on the 5/8" hose; standard garden hose size.

 

[Bolisk]

Good point. I guess I was assuming that the hose that was connected to the water pump was the input, and the one that connects back to the intake manifold was the return. Looks from the photo, that it's connected to the retrun.

 

[paul67]

Whatever way, the coolant will not flow to the core when that valve is closed.

 

[JohnZ]

The 5/8" hose from the intake manifold fitting goes to the heater core inlet nipple (also 5/8"), and the 3/4" hose goes from the heater core outlet nipple (also 3/4") to the water pump fitting. The shutoff valve always goes in the 5/8" hose.

 

[Bolisk]

JohnZ,

Have you ever changed a heater core on a non-AC car, through the Fire wall shone in the link at the top? Or have you always pulled the dash appart?

-Bolisk

 

[JohnZ]

JohnZ,

Have you ever changed a heater core on a non-AC car, through the Fire wall shone in the link at the top? Or have you always pulled the dash appart?

-Bolisk

I've never owned or worked on a C3; on a non-A/C midyear, you have to remove the inside heater box from under the dash to change the heater core.

 

[paul67]

I've never owned or worked on a C3; on a non-A/C midyear, you have to remove the inside heater box from under the dash to change the heater core.

I don't know why you can't see how it is done from the pics??

http://www.corvettefaq.com/c3/heatercore.html

 

[LVMYVT76]

on my 76, a/c car, I pulled it from the inside, had to tear eveything apart.