1969 - 1970 Heater Core Replacement & Dash Disassembly

by | | 0 comment(s)

Heater Core Replacement & Dash Disassembly - 1969 - 70 Cougar & Mustang - How-To Video

Ready to tackle replacing your heater? Check out our Heating and AC Components.


Well, it's that time of a car's life we all dread: it's time to do the heater core on this old car. No kidding, it's a tough job and a lot of you are going to think "I'm just going to take it to a shop." That could be a mistake, because a lot of those shops don't have the patience or love for your car that you do. So let's dive into this together, maybe you'll learn something here and you'll be empowered once you watch this video and feel like you can handle it.

Normally I'd remove the console, but since I was working on my radio and repainting my console, that part's already done. So, another piece we'd have to take off is the radio trim - already done. So next we'll start working on the fasteners: here, here, three of them up here, then we've got the little ones underneath this trim, we've got a couple here, and then we've got a couple here, and here. So we've got lots of external screws to remove. Unlike the 67 or 68, this dash pad is relatively easy to remove. It helps to have a convertible!

This is a critical point right here: the speedometer cable has to be squeezed right at the head in just the right place. If you yank on it, you're going to break the plastic clip, and you'd have to replace the whole speedometer cable. So we're going to reach back there and squeeze it just in the right place - perfect! This is what you're doing, you don't want to squeeze like this, you're doing nothing, you want to squeeze - you want to push this down, and when you push this tab down you're releasing that right there. That's the locking pin, if you will, so you push down and pull the cluster out.

You're going to come across several fasteners that are like this, that are embedded in there, and you need to take - so squeeze like that and pull like that and they come right out. These are the types of things that the shops often ignore and they just pull those out and they figure, "Oh, we'll get new ones." Well, where are you going to get new clips here and there and everywhere? You aren't!

[After removing the lower dash] Well you might be thinking, "Wow, this is going pretty easy!" Taking it apart is the easy part. I hope this video helps when you go to put it back in; you're going to see how those wires are routed and everything. Label your fasteners if you have to. I've done this enough times, I know what goes where, but some people like to use a cardboard piece to lay it out, and as they take the fasteners off, punch them through the cardboard and label them.

You might be inclined to avoid taking out more than you need to, but be forewarned, to get this out you're going to need to at least loosen this up from the other side and from here. So the whole blower motor assembly is going to have to get shifted over to be able to get enough room to get this out easily.

An ounce of prevention is better than a pound of cure - maybe you want to label some of these, like to this little vacuum actuator. We have an upper hose and a lower hose. Yeah, the lower hose is the one that broke off; that's how we'll remember that!

Now here we're like, "why isn't that coming off?" Well, I have another example right here. This is what it looks like here, right? There's your hidden fastener. We have another one of these embedded right here. There it goes.

Here's an area that's always prone to failure on 69 and 70's: the trap door inside here hangs up. So you're going to be tempted to just test it this way, by putting your thumb here. Well that doesn't give the full story - you actually need to replicate what the car is doing, and the car doesn't have fingers sitting here doing this, the car has vacuum. So we apply vacuum to this vacuum actuator to see if it's moving freely. [Sucks on vacuum hose] See how it was hanging up there? You've got an obstruction here in this linkage. Many times when you get in here, you'll see this little plastic arm is broken. We're one of the few places where you can buy that little plastic arm. We've got to figure out what's obstructing that flap door so it doesn't break in the future. We're here, we might as well do it. This is one of the things the shop has no clue about, and they don't care about. They're doing your heater core.

Before you even crack a screw or loosen a line you need to determine if you have refrigerant in your system still. If you do, don't waste it - take it down to your local air conditioning service shop. Have them evacuate it; they can filter it, store it, and when you're done with the job you can come back and get that same refrigerant put back in your system.

You may be thinking, "What's he doing, dismantling the car?" Well, there's a reason that the air conditioning was so expensive. It's pretty involved here, I mean, it touches a lot of this car. So here we go, here's the under hood part. A lot of people forget this. I'm encouraged again, nobody's been here - look at this fastener over here. We're going to be taking that out. See the undercoating on it? That's never been out.

[After removing lines, fasteners and seals] And that concludes our under hood segment.

[Back inside the car]

Scott: "Did you get your drain plug?"

Don: "Yes."

"Your drain hose, rather?"


"Are you using sound?"


How am I going to remember those? [Vacuum hose locations]

Mission accomplished! This is what we want to see. This bracket hasn't been broken off, this bracket has not been broken off, the drain cock has not been broken off, we were able to get these out without compromising anything, nothing's hurt. This is a big deal. I've seen people pay shops hundreds of dollars to annihilate one of these boxes.

Once you get this out you need to treat it like a $500 piece of glass, because that's what it is. This is fiberglass. It's old, it's brittle, it's been subjected to heat, it's been subjected to cold, and moisture, and it's valuable. Yeah, $500 valuable believe it or not. Treat it like it's glass.

Now, I've seen pros tackle these all the time. The first thing they do is, they take their screwdriver (and I'm talking about so-called pros here) and pry the clips off. You can't pry the clips off; you will break that little lip right there. Again, this is fiberglass, this is 40-some years old, this is brittle. You don't do that. These clips are designed to be lifted off. Hear that? There was no snap, crackle, pop. If you pry it off, you'll break the fiberglass. Again, you just put the screwdriver in here and lift them off. And, we've got to go get a nut driver again. 5/16" it was.

Looks like we need a new seal kit - look at that. Let's put a little WD-40 in here, this flapper has got to come out. And just so we don't break anything, let's take this off.

Okay stop right here, I'm making this look way too easy. A lot of you guys are going to get in there, you're going to find mouse nests, you're going to find coolant leakage that's going to corrode everything. It's a whole different ballgame when you have a car that's a mess. This one was clean. So do know sometimes this takes sandblasting, patience, wiggling, soaking, finesse, and a lot more. Again, that shop doesn't have time to give the finesse that I just gave this, or you might have to give it, so this is one of those jobs that maybe only you are going to be able to do.

I'm not going to walk you through a complete restoration on one of these plenums - probably because this one doesn't need a plenum, and I'm not the most qualified guy to restore one of these. I'm just going to service this one. While I'm here, I'm going to give you some tips. Number one: you're going to be tempted to buy a new high-efficiency evaporator. They are higher efficiency, I'll tell you that, they're expensive! But, more coils means thinner coils. They don't hold up forty years like these. If at all possible, keep your original. Even if you've twisted off one of these ends, they can be put back on. Even if some of these fins are a little warped, you can gently go in there and massage these fins with a screwdriver, needle nose pliers, a popsicle stick, whatever you have. These are worth putting the time into.

This little gasket is not available yet, but Daniel Carpenter Mustang Reproductions and I are working on a reproduction of this. There's a couple different versions. [Editor's note: they are now available]

All these pieces, if you have any lost or broken, are available new or used. A quick little test on this - this is a vacuum gate valve. So you're going to want to see that the spring action is still good. You're going to want to see that it actually shuts off the flow of vacuum when you open and close it. If it isn't, these are available new on our website.

These vacuum actuators, if you don't have a Mityvac, or Snap-On, or whatever, a handheld tester, you can do it the cheap way. You can just go like this, watch [sucks on hose and holds finger over it] - it if it creeps up, you know that the diaphragm inside is bad. It should be able to hold indefinitely. So we have these used. The clips, we have reproductions, but when you look real close (and we have some detailed pictures on our website) they're contoured a little differently. They don't fit as good. So we have used clips as well as the reproductions on our website.

Heater cores - don't buy the aluminum ones. These are a pain to get out, as you've seen, and we've found the aluminum ones don't hold up as well. Yes, they're $15 cheaper - it's not worth it. So, get a quality-made brass one like we have on our website, pay a little more. Secondly, these pads. We have these on our website. I don't usually recommend you replace them, reason being they don't go bad. Unless you got mice damage, don't mess with it. If they stink like mice, throw them away, buy new ones. But again, after 40 years, these ones look great. I'm going to reuse mine and save a few dollars.

Okay next on here, the blower motor assembly. Again, you're going to be tempted maybe to say, "Well, since I'm in here let's buy a brand new motor." If your motor isn't howling or vibrating and still throws out a good speed, stick with the original. If yours is sounding tired, maybe you should get in there and see if you can service it. Again, most of your electric motors these days are offshore and don't hold up for 40 years. We have good used ones that we actually test and lubricate and service and put a warranty on. Yeah, we put a 90-day warranty on a used electrical part. So again, new is not always better.

A certain guy that runs a camera here at West Coast Classic Cougar was was just working on his flapper door here, and he couldn't get it out, so he pulled, and pulled, and pulled... Guess what he did? He broke right through the fiberglass. I say if you really have to get this out, because you want to bead blast it, and paint it, and make it beautiful, sacrifice this part. Cut through the rod, throw it away. At all costs, protect your fiberglass. We have replacements on this stuff.

Once again I want to stress, you don't snap these on. I've seen experienced mechanics much older than me, that have been working on these for years, just pop put these on. Don't do it - you're going to break that little fiberglass lip there. Take your time on this procedure, open the clip up and put it on.

Well, it's time to reassemble this. Some time has passed, more time than I want to admit. Isn't that always the way it is with projects though? I really wish I'd taken my own advice of putting all these fasteners in a piece of cardboard and labeling them. Now I'm looking all these and I'm pretty sure I know where they all go, but I'm a little foggy. Before I get started here, I'm going to start rounding up parts. I've already rounded up a few. One is, I want to replace all these bezels. Mine are all pitted here, and I've chosen to go with nice originals because I want this to be an unrestored car, and stick with its original patina. But if you're going all out and restoring your car, we have every one of these reproduced, and they're on our website. Plus we have the little tool - each one of these requires a different tool, and it sure is nice to have the right tools, as opposed to a screwdriver and pliers or whatever else we might use.

A little tip on your air conditioner bezels / registers: they're two sided. So many of them have sat one way all their life and they've been rubbed on and had 409 put on them. If you want them to look new, just rotate them in their socket, and there you go, you've got a brand new look.

Your instrument cluster: we have all new lenses available. These look nice, I'm just going to take these out and polish them and reuse them. A lot of them have gone milky - that milky color is internal; you're not going to buff that off. Fine scratches you will buff off.

Bulbs: I have two or three bulbs burnt out, but all these bulbs are old, so let's replace them all. They're only a buck or two.

Printed circuits are easy to diagnose. If there's a burn spot in them, or they're delaminating, they're bad. We've got these brand new on our website.

Tachometers: We've got brand new ones, and we have good used ones if yours is bad.

Constant voltage regulator: these are mechanical, they're prone to fail. We now have a solid-state one - something to consider.

Clocks: they're all bad. There's no such thing as a good used clock (very few, anyway). We convert them to quartz. We have a guy that just does a beautiful job. He even restores the back side. We put a brand new lens on them. For some reason these are more prone to going milky than these. I think it was a different supplier or something on the acrylic. So, every one of our rebuilt clocks has a has a brand new lens. And again, you have to take the dash pad off to do the clock; now is the time to do it.

These knobs are available reproduction, but mine aren't peeling, so I'm going to leave them alone.

I'm getting back into it, and really it's not that bad. Once you get your mind into it, and you get the flow going, it all comes back to you how it went together. These vacuum hoses are all color-coded, and of course we have the diagrams, as does everybody else, and the schematics that tell you where to go. But you're going to be looking at some of these (especially you colorblind people) and you're going to go "what color is that?" After 40 years it's hard to tell. Is that a white stripe on there? It's so faint. Well, if you just listen to it, it'll tell you where it goes. I mean, look, on a used part like this, where else would it go? That's just an obvious one. The length on this tells you where to go. The beauty of the electrical on this is Ford made every plug different. They were color coded in a different shape plug, so on the wiring harness it's almost impossible to get it wrong. What you will get wrong is the way it's routed, and sometimes you'll have to back up and undo some stuff to get it to route right.

One of my number one hang-ups when I'm going to reassemble is sequence. Inevitably, I get this lower dash in and I realize, "Oh no, this should have gone in before the lower dash!" What helps me is to take some digital pictures here. It's just too easy not to. And then if I want to know what fastener goes where, I can scroll back through this and usually figure it out.

Here's one thing everybody overlooks: look at these diffusers here. Mine are all burnt, and the ones that weren't burnt were hazy. And when I look at that sign over there, I can't even read it. When I get the brand-new ones out of the package and look across the room at the sign, I can actually read it. This makes a huge difference. You can also get them in custom colors (yellow and red) but I like original.

Last few tips as we wrap up under the hood and tie this project up. We got cork insulation tape - this is old-school stuff, and a lot of your shops probably aren't using this old stuff. We have it on our website, it's dirt cheap. This is what insulates and wraps your A/C hoses going into the firewall, and the probe there. Also, you don't want any fumes in the car, so this ribbon caulk, 3M ribbon caulk, on our website (again, cheap) goes along the perimeter of this between the firewall and this two piece plate.

It's only a few dollars more we might as well get the concours-correct, Autolite insignia, date coated hose with the correct bend in it. Makes it a lot easier installation in those tight areas on a big block.

These are the correct tower clamps, and 90% of all the ones on the websites out there are the cheap kind. This is the quality kind, and they're actually about the same price, maybe less, than the "el cheapo" version.

Lastly, you're going to wonder what this is. Well, from the factory, they put this in as a protective measure, so when the engine was being lowered in it didn't bump these pieces. It would instead hit this. They were supposed to take it back out as a cost-saving measure, but I think they realized it took more time than it was worth, so they left them behind.

You know, once I got back into this project after letting it settle awhile, it was fun. It was a challenge, frustrating at times, but at the end I'm like "hey, I got it done!" and I think you can too with some of these tips. Take your time. These are expensive parts, hard-to-find parts, but you shouldn't have to do it again for another 30 or 40 years if you do it right. Good luck!

This entry was posted in .

You must be logged in to post comments.