Heater core

[panel 10]

Hello, I'm new to this forum and it looks like a god one.My son has a 69 Mustang fastback that now needs a heater core replacement.

I see threads on the subject but I'm not clear if a car like my sons without air conditioning is easier due to not having to take the dash out.

Some say they just take the glove box out and some bracket bolts , then lift up to snap off some clips.

Are all the clips accessible ?

Thanks

[Rsanter 152]

Remove dash pad

Remove glove box

Take lower dash loose on the pas side and pull back on it a bit

Use vise grips to hold lower dash in place while working

This will give you some added work room

 

Replace heater core

Reassemble in reverse

 

Of course the best way is to remove the dash and the whole heater box.

It not as hard as you might think

 

Bob

[Mike65 475]

The way I was taught how to replace a heater core by an "older" Ford mechanic was to, drain the coolant, unhook the heater hoses from the heater core, where the two halves of the heater box come together there are these clips

http://www.cjponyparts.com/scott-drake-heater-housing-clip-pair-1965-1993/p/HW605/

using a straight blade screwdriver pop them off & remove the rear section of the heater box exposing the heater core. Do NOT miss the clip that is up against the kick panel. Remove old heater core & reverse order to assemble. The clip up against the kick panel can not be re-installed with the heater box installed. The other option is to remove the complete heater box by removing the 3 speed nuts under the hood, unhooking the blower motor wires, remove the heater hoses from the heater core, remove 1 screw from the bracket from the heater box to the cowl, & then remove the complete heater box. I have personally done it twice on my own cars by just removing the retainer clips & removing only the rear section of the heater box.

[panel 10]

Thanks for your replies and Mike , your car is going to be a solid nice car.

[Mike65 475]

Thanks for your replies and Mike , your car is going to be a solid nice car.

 

Thank you, it is getting there.

[69FORD 1]

Hi.

I own a 69 Mach 1.

It has factory AIR/CON... The Heater core obviously leaks as the core hoses have been cut and sealed off  in the engine compartment.

 

I have read numerous feeds concerning heater core replacement  BUT  can it be done without removal of the whole dash assembly ?   ie  radio out, dash pad out etc ?

Is it possible to replace the heater core by just removal of the glove box and will this allow enough access to removal of say the bottom part of the heater box to get at the heater core?

 

if you have done this Id be appreciative of your feed back

John QLD Aust 

 

[danno 128]

11 hours ago, 69FORD said:

 

John in Australia,

If you have AC, it is a huge job.  I know of no easy way to do it.  You will need to remove the dash, dash panels, lower dash ( where the lower AC vents are) and then keep going from there.  I am not even sure if you can do it without removing the AC freon lines.   When I did it on mine, I think I was able to do it, but it was very difficult.   Others might know if there is an easy way, but I am not aware of it.   Good luck. 

[Shep69 149]

15 hours ago, 69FORD said:

Hi.

I own a 69 Mach 1.

It has factory AIR/CON... The Heater core obviously leaks as the core hoses have been cut and sealed off  in the engine compartment.

 

I have read numerous feeds concerning heater core replacement  BUT  can it be done without removal of the whole dash assembly ?   ie  radio out, dash pad out etc ?

Is it possible to replace the heater core by just removal of the glove box and will this allow enough access to removal of say the bottom part of the heater box to get at the heater core?

 

if you have done this Id be appreciative of your feed back

John QLD Aust 

 

John , I had the same issue with my Mach 1 . The simple answer is no. If you've got an original a/c plenum in good condition treat it like a $500 piece of glass. Even taking the clips of splitting the plenum needs to be done carefully. I had to remove the entire dash to get at it . It's one of the bigger jobs you will do but well worth it. While apart you can replace all the seals and even the AC evaporator if needed. I even painted my dash while it was out. 

 

[69ShelbyGT350H 61]

12 hours ago, danno said:

John in Australia,

If you have AC, it is a huge job.  I know of no easy way to do it.  You will need to remove the dash, dash panels, lower dash ( where the lower AC vents are) and then keep going from there.  I am not even sure if you can do it without removing the AC freon lines.   When I did it on mine, I think I was able to do it, but it was very difficult.   Others might know if there is an easy way, but I am not aware of it.   Good luck. 

I agree. A/C core is on the top and Heater core is on the bottom. It is very hard to get to all the clips that are between the plenum and firewall off while it is in place. If you do not want to discharge your A/C, you might be able to remove the upper/lower dash, remove the bolts that hold plenum in place, then see if you can move the plenum into the passenger compartment enough to remove the clips and drop the bottom half down and back. Take the clips off by putting a screwdriver in the folded over ends of the clips and levering the screwdriver handle toward the other folded then to spread the clip open and off the plenum.

Here is the firewall side.

 

 

 

Here is the lower half with the heater core. The A/C core will stay in the upper half. The A/C lines go in the lower half via a rubber grommet that should detach from the lower half.

 

Here is my plenum after disassembly, cleaning, repairing broken/damaged areas, painting the metal rods and flaps, installing the new seal kit, and a new heater and A/C core.

[fvike 173]

About the clips that hold the two halves together; when assembling the heater box, DO NOT just pop them in place. They may damage the fiberglass. Hold them in place in one groove in the heater box, then use a flat head screwdriver in the "pocket" of the clip an lift the clip in place in the other grove.

[Bob & Sue 110]

I will admit I didn't do the replacement myself a buddy that owns a restoration shop specializing in Concours Vintage Mustang & Cougars did mine while I helped & learned.

I have a 69 with factory air there is no way to replace the heater core without the removal of the dash if it could be done folks would do it. Even if you could several of the clips holding the heater box together aren't accessible. After the box is out be very careful with it they are 50 years old & replacements cost top dollar. Yep you do need to remove the lines & plates in the engine compartment.

The clips holding it together need to be removed carefully by pressure with your finger pressing them in to release the tension then removing them, if you use a screwdriver or pliers there's a good chance you'll break the box they're very brittle. 

Warning ( in the 50's thru 80's they made these boxes out of what looks like fiberglass layups they're not ) heater boxes & fan shrouds are made of a combination of materials they can contain as much as 50% asbestos. I have a book from our attorneys when my father died of Mesothelioma quite a few parts on classics have asbestos in them even the carpet whenever removing old carpet spray it down with water before ripping it out or cutting it.

[Shep69 149]

West Coast Cougar had a great video on this . I used it when I rebuilt mine. It's now been deleted. I emailed them yesterday and got a reply saying they deleted it as they are working on a new video with their new plastic plenum. Would have been good to share as it shows everything from pulling it out , rebuilding it and replacing it. All the little tricks along the way. Hope their new video covers all this. They sent me a link to the new plenum. https://secure.cougarpartscatalog.com/heater-box-with-a/c-repro-1967-1970-mercury-cougar-/-1969-1970-ford-mustang.html?attribs=87

[JD08 42]

I just finished putting mine back in the car without disconnecting the AC lines and you absolutely have to remove the lower dash. I patched up the old box with fiberglass and noticed that about half the perches the clips rest on were damaged prior to my disassembly. The WCCC video was a godsend in that whole process, especially since it was almost a year between disassembly and reassembly. 

[Wildpat 0]

On 9/23/2014 at 3:29 PM, Rsanter said:

Remove dash pad

Remove glove box

Take lower dash loose on the pas side and pull back on it a bit

Use vise grips to hold lower dash in place while working

This will give you some added work room

 

Replace heater core

Reassemble in reverse

 

Of course the best way is to remove the dash and the whole heater box.

It not as hard as you might think

 

Bob

What he said ^^^^, though I'd recommend removing the whole assembly for a thorough overhaul. Leaving the front part of the box in place makes it hard to access all the clips. Your choice. Removing the heater box allows for visual inspection of that firewall section which is good!

If you decide for the removal, clean and lubricate the gates. The core may need some adjustments done to the box. Get a replacement Aluminum core, unless you are going for all OEM restoration.

It is also a good time to clean and repaint the whole box, rust proofing all metallic parts, check and maybe overhaul the fan motor (or replace), replace all the rubber seals as they are certainly gone to dust. As well, check and eventually replace the cables, the hoses, the clamps, the clips and the resistor. 

Removing the thing is a major PITA so you want to do it thoroughly and NOT go back to it any time soon!

 

[danno 128]

One more suggestion about those spring clips.  I am not sure if it is possible, but it might be better to put an extremely long hose clamp around the thing to hold it together.  It would save the risk of damage with those stupid spring clips.   You can buy fairly long hose clamps, and tie several together to go around the whole thing.   It will make it easier to replace the next time.   When I do mine again, I am going to try this.  Those spring clips are not easy to use and damage the enclosure.   

Just another idea.

[moodster 55]

Having recently rebuilt mine, I think Ford built the 69's around the heater box.  It certainly is one of the harder jobs I've done on the car.

[69FORD 1]

Thank you to all for your valued input/

To date I have avoided the major operation on the heater core, partly due to having factory fitted Air con AND in Queensland we dont need a heater at all.

 

 

So taking into account such a  big job I will soon order lots of parts including those dastardly clips  and put it off the road and DO IT

 

 

stay tunes and thanks again

John

[larryc94 38]

Remove  it completely, replace seals in box (like $10) and a good time to replace firewall pad

[69ShelbyGT350H 61]

5 hours ago, 69FORD said:

Thank you to all for your valued input/

To date I have avoided the major operation on the heater core, partly due to having factory fitted Air con AND in Queensland we dont need a heater at all.

 

 

So taking into account such a  big job I will soon order lots of parts including those dastardly clips  and put it off the road and DO IT

 

 

stay tunes and thanks again

John

It's not the clips themselves as much as the damage they do to the box in the areas that they hold it together. The box is brittle after all these years and cracks or comes apart easily where hardware attaches to it. I used JB Weld to fix cracks in the box as well as damage areas where the clips go.