1973-87 Chevy & GMC Squarebody Heater Core Replacement 

I do not think anyone could do a better tutorial. You are the BOSS!

I'm already an experienced mechanic. But your simple step by step instructions really helped me skip taking extra stuff apart. Thank you for your clear step by step instructions.

Great video, I used the information to replace the heater core on my 1979 gmc 2500. But I didn't find any pudin pie. I am handicaped by a broken back and I am alone. Puting the heater back in was a real chore. I used one of my crutches, I laid the crutch across from the cowl to the radiator mount. i used a cheap little 1 inch strap come along, I wrapped the strap around the heater through the hole in the firewall and hooked both ends to the crutch and hoisted the heater up until the heater bolts lined up with the holes in the firewall and to my relief, I was able to push the bolts through and put the nuts on. I rested 5 days before I could continue.The heater is in now and working good. Thank you for the very good video. wil

Thanks soo much. On ‘84, the damper door pin actually went all the way across the housing and had to be removed before I could separate the halves to get to the core. I also had to separate the upper vacuum pod which has a little screw inside the housing. It was a bit more involved than this one but this definitely helped. I bought the core from Summit, much better than the aluminum ones from elsewhere. Lets hope I never have to do this again. Thanks!

Thank you for the video and your tips!!! I changed mine today, '79 C10. The tape on the socket and swivel worked great.

Excellent tutorial ! I have to do all that and have been fretting doing it, but with your video I think I can "get er' done" ! Thanks !!!!! *****

Just finished up my 86 K20 Suburban, Could not have done it without this video. Great Work!

Great info! Only thing I did differently was to use line clamps on my heater hose so I didn't have to drain the entire system. Just put a water pump on a couple of months ago so all coolant was fresh.

Thanks for this video. Just replaced it on my 82 C10. Pretty simple step by step. Much appreciated!

Great job explaining the steps !

Thank you, this was very helpful for me, now I can exchange the heat exchanger to my 84 C10. Have a good time, greetings from the Black Forest

Thank you so much. This helped with me 1988 GMC suburban. Its a little different but your video got me through it. 😂

Awesome video. Now I feel confident that I can get this done 👍

Thank God for Dave Welch!

Best video by far I've seen on this job. The heater box control cables on my '78 have had me a little spooked, but I think I get it now. Thanks.

Very good video. Sometimes you can take a 90 degree pick under your hoses and work them loose. Also, a set of swivel sockets and wobble extensions are amazing.

Thank you so much I really appreciate your videos 👍👍💯💯

Excellent video!

Thank you for making this video.

So it's basically a 20 min. job.😁😁😁 As soon as the weather warms up I'll probably tackle the 84 Scottsdale. Very good tutorial! Not too long but with plenty of detail.

Holy mackerel! Got it done!!!!

Thanks man just changed my heater core on my 82 k5 blazer

I’m doing an LS swap as we speak and this video is going to be very helpful to me. Thanks and keep up the good work.

Great detailed video.

I'm watching, great info.

Best video on this now time to get to work

Great info... Currently working on my 73 with no factory a/c but it has aftermarket a/c set up.... But it seems kinda easy but s lil time consuming but dealing with it

Thank you!

Good job!

It's been awhile since I've done a heater core so I decided to look up a video to give me a refresher. The books telling me to do things that aren't required. Speaking of things that aren't required let's discuss those two studs that are at the bottom of the airbox going through the firewall especially the one that's near impossible to get to. I could not get to it. I was going to remove my fender well but somebody modified things that can't be removed without cutting them so I cut a hole in the fender well where that nut was. Once I got everything out I realized that putting those studs in from that direction was such a horrible design. They could have easily fixed a stud to the firewall with a thin nut holding it in place and had access to remove the nuts that hold it in from the interior rather than the firewall. If I didn't know better I would say it was a deliberate asshole design. So when I put this air box back in I'm going to put two studs in that firewall with a thin nut holding them in place permanently. If I ever need to remove the air box in the firewall it's a simple as doing the very thing I have to do anyways and then removing those two little thin nuts that hold those studs in and the whole thing will come out with the air box in the firewall. All they had to do was flip those two studs around. Book says this is 3 to 4 hour job. When you eliminate that one stud with that nut you can't reach this becomes an hour maximum. It literally took me about 10 minutes once I got past that.

Thanks for the great information

Good video

Great video as usual! Is there any chance you have a video for the 67-72 C10 with A/C heater core replacement? I figure it's basically the same, but I can't find a single video showing it done with factory A/C. Thanks in advance for your response.

Thanks.

for the "quick tip" part, just put grease on the nut & it will stick to the socket & won't fall out.

The original foam came off of the flap/blend doors. Is this a requirement? I have an 1980 K10, any good places to get the seal kit for the heater box?

What's the best brand Heater core, or should I have my Original OEM one rebuilt, it isn't leaking 14:08 leaking but I'm installing new carpet and I don’t want to chance it leaking on my new carpet its a 1975 Chevy K10? Lmk cuz I'm going to start soon.

Thanks have to replace my son's tomorrow on his Suburban.

My trucks been sitting for 15ish years before I bought it, mostly in fields. I want to go threw all this to get it out of the way and figured I should replace the vacuum pods mentioned while I’m in there. In the site I only see them for a 67-72 a/c air box vent actuator and the 67-72 firewall vent actuator. Are the vacuum pods for the 72 the same as they would be for a 74?

I just discovered that I could have installed a copper, brass heater core for about $70 more than the aluminum one that I installed. If this aluminum one doesn't last I am going to be very disturbed. I would have bought the copper, brass one had I known. This job was way too much labor for me to do again. But If I live that long (Iam 87 now) I guess I will do It again. I just can't trust many mechanics. wil

I have yet to see anyone talk about the air cleaner system i have a 1982 gmc s15 high sierra and a lot of hoses are missing, cut or disconnected. If you could do a rundown on that you would be like the only one to cover that on youtube

Ive got tons of sunflower seeds and insulation pieces from a rodent that made the heater core housing its home as you mentioned. I cleaned one side by removing the plastic pieces you show in your video giving me access through the blend door opening but cant access the side closer to the blower motor. Will removing the blower motor give me access to the housing box so i dont have to completely remove it like in your video?

Exactly what I told my mom I should do is do the AC and the heat are cool all at once but she wants me to do the heat accord and then go back and do everything all over again

Just saw this really wanted video of yours because… I need to replace my heater core on my 1988 K5 blazer! I saw another video and ran scared of the trouble the other guys went through. Nonetheless, your process seems a little more reasonable. What differences should I expect to find against this truck model you performed this job with? Now, my vacuum lives do not seem to be working at all since air comes out of everywhere on whichever position I place my controls. Any advice you may provide me before I order my parts and start my job? Thanks a million !

Where can I get the vacuum lines? I need to replace 2 vacuum lines..

Thank you sir video was great very helpful

You could go as far as removing the inner fender as well

Hey my gmc 1978 heater doesn’t work will this help it and do you have a video on how to fix it

Also, where can I find all necessary pieces for the ac compressor mounting bracket?

do you have a link to that vacuum pod on the hvac unit? tried looking on the site but wasn't able to find it haha

Doing my 86 right now and it appears to have a one piece cover on the heater box so it looks like i have to pull out a pivot shaft from a divider door .

I'm not sure if I've ever had to jaggle before. I'm gonna develope a situation where I need to jaggle.

Do I have to put that big ac tube in seen at 12:40 if i deleted the ac?

Anybody else notice that the fuel line is wrapped around the AC accumulator to keep the fuel cool when its hot out. Not too bad of an Idea.

My ac equipped 86 c10 has a plastic plate that covers the entire heater core up to the inlet and outlet and after I removed the 4 screws from the blender chamber and the cable bracket, I still can't get the whole heater cover to lift up. Only the inlet end will lift up a half an inch. It's binding up at the blender door hinge area and I've removed every screw and clip I could see. All vacuum pots are plastic. I haven't removed any of the operating rods connecting any of the posts to their doors yet. Any advice?

Wow they sure dont make them like they used Too. Barely had to pull anything out of that truck to remove the box. These newer cars you gotta remove the column and whole dash

Can you do a heater core replacement on a 67-72 GMC or C10 pickup with factory A/C ?

I have a 1979 c10 that is leaking coolant in the passenger side of the cab. Both the ac and heater don’t work would this fix my leaking problem?

What would be the best way to clean these plastic air ducts? Truck im working on has been sitting with animals (mice) living in it. Has a smell to it. Would warm soapy water be enough to do the trick?

Would this procedure be the same for a '76 El Camino?

At 9:44 the bracket that you have where can I find one? Or what is the part number on that

So the entire blend door unit on mine was plastic so I have to take the whole thing apart to get the core out of it

I'm looking for all the vacuum actuators for a 86 C15

I think we could use a detailed step-by-step explanation on how to replace that little plastic piece that opens and closes the vent door. The little white plastic piece that always breaks.

What brand of core do you recommend? I just put a Spectra (that came in a Murray box, go figure) in mine and it fit like garbage. Some liberal application of a small hammer got it to fit into the module, but I'm not opposed to doing the job again if there's a different brand that fits decently. Side note: the design of the factory heater core is laughable. There's nothing wrong with mine, but it allows so little airflow that my heater couldn't keep the windshield defrosted at speed.

Can you guys @ (BTP) make video on how to Muncie 4soeed or Turbo400 transmission swap on 1960-72 Chevy/ Gmc truck.

I would love it if you could tell me where those seats came from

So what would cause coolant coming through the dash? Would this be it?

How much would it cost for a shop to do this minus parts? how much money in labor does this save about

How much would it cost to get a shop to do this minus parts, just the labor. How much money is all that saving?

Hey those seats in that truck are really nice. Can you tell us about them so we can upgrade to ones like that, or if you already made a vid about them shoot me a link

Hello,i have an 88 blazer and every so often while driving my ac will stop working and no air whatsoever will come through the vents.Where do you think the problem lies,a faulty low pressure ac switch,bad resistor,or a failing blower motor,thanks for any help!

Is draining the radiator really necessary? Cant I just tie the hoses up to the hood? Thanks for the great video

Is it ok to restore my factory ac or is better to buy a new ac system ?

Is this the same in a 1990 suburban?? It all looks the same idk why the model years show different mine is a 90 and it looks just like every 73-87 I've ever seen. I need to do mine.

holy fuel line... what does wraping it around the ac do?

I notice the fuel line wrapped around the condenser. Is this a southern thing because of high heat?

Would an 89 Suburban follow the same procedure to change heater core

It took you 14:08 it take me 36.10hours 😭😭😭

Can you guy take look at your air conditioner. I just pai 600 dollars and the next person I took it to messed it up what can you do for me

I had to put a new heater core in my 86 6.2 deisel truck

Why is it all the videos I look for on you tube cover everything EXCEPT 1988? They all skip over 1988.

Woulda been more helpful about a year and a half ago😂

Electric Ratchet man, save your wrist. You don't realize how much you use your wrist until it's painful to do anything.