I replaced the heater core in my '87 IROC last night, here are some notes from the job.

This is the second time I've had to do this in two years. The core that started leaking after a year was purchased at AutoZone for about $25. This time I paid $39 from a local parts house, hopefully this one will last longer.

A 1/4" drive ratchet makes the job easier. The 3/8" ratchet with 1/4" adapter is much harder to work with.

After searching posts on this topic, there were some people who recommended taking off the dash pad, some said they didn't need to. I did not take it off. If you're doing this job for the first time, removing it may help you see what you're trying to do, but I was able to get to everything from underneath. It only takes an few minutes to do. The first time I did this job, I did not re-install the top screw securing the heater box cover. This screw is hard to get to, you'll be in an awkward position and not be able to see what you're doing. If I had to remove it again I would try using a 7mm box end wrench, the smaller the better.

I took out my passenger seat to make more room to work and placed a welcome mat on top of the studs on the floor so they would not puncture my backside. Only takes 10 min to r/r and reduces frustration when trying to work under the dash in tight places. Also removed my T-Tops.

I did not disconnect my battery. I like to listen to my stereo while working. I did not drain my radiator. I do that in the spring.

The part of the job that took the longest was getting the heater hose (the short one, running from the core to the back of the engine) re-connected. I put Vaseline on the end of the hose to get it to slip on easier. Thinking about it now, it would have been a good idea to put some on the ends of the core tubes. This is a tight space, with the transmission dipstick tube and wiring harness as obstacles. Work the hose back and forth, up and down, until it finally slides on. I used the screw-on type clamps to secure the hoses to the tube ends. Getting the hoses off took some persistence too.

Putting the new core in, I initially had some difficulty because I used to wrong method. I placed the core in the heater box and then tried to shove the heater core bracket in next to the core, but it would not go in right. I took the core out and placed it in the bracket, then placed the core/bracket assembly in the heater box, lining up the core tubes with the holes in the firewall. Went right in.

It sure is nice to have a Shop-Vac to clean up the floorboard of spilled coolant. Before installing the new core wipe out the inside of the heater box with an old towel.

To summarize the steps in replacing the heater core-
With a cool engine, disconnect the heater hoses that attach to the core. They are located between the transmission dipstick tube and firewall under the hood.
Remove the 7mm screws that secure the cover to the heater box, remove the cover.
Remove the 7mm screws that secure the core/bracket assembly to the heater box, remove the core/bracket.
Remove the bracket from the old core and place it on the new core.
Install the new core\bracket assembly in the heater box, install the cover.
Attach the heater hoses.
Note: this works for an 87 IROC. It may or may not work for Firebirds or other year Camaros.

Did I leave anything out?

This is not a complicated job, but it can be frustrating because of the space constraints, the somtimes awkward body positions required to get to the components, and having to work by feel, not seeing what you're doing.

If you've not done a heater core replacement before, I would recommend doing it on a weekend. Take your time. Don't be concerned that others can do this job in 45 minutes and you can't. The first time you do it will probably take several hours, the second time only a couple. Patience, persistence, and determination are the key ingredients to success.

When searching for other posts on this subject (there are alot), 'search titles only' will give the most relevant results.

Click here to go to the tech article on this site

 

Pictures?

 

next time try putting permatex on the insides of the hose. the kind in a can with the brush in the lid. besides helping it slide on it makes a good seal and you'll never have a leak if you have the hose on right and tighten the clamp down. i just did a heater core 2 weeks ago in a grand am. wasn't bad far as heater cores go but it wasn't a good job either.

 

I'm dreading this job, but it's freezing outside, so I need to do it this weekend. How long should it take?

 

I see by your sig you have a TransAm, I've only done my IROC. I would count on taking all of an afternoon for starters, maybe more. A more accurate estimate would come from somebody who's done a car like yours. Search on 'heater core' and select 'Search titles only' for more info.

 

Yah,
Don't put that friggin top screw back in that holds the cover on. You'd be able to do the job in about 15 minutes next time it goes!

 

I've heard that the top screw is a problem, but frankly it wasn't for me. Check the following link:

https://www.thirdgen.org/techbb2/sho...hreadid=210395

JamesC

 

Well, I got the job done today, here are the results.

Whole job, start to finish took one hour and 45 minutes. Lower kick panel came off along with the dash pad. I took out the speaker and stuck my hand through the opening to get the top bolt. I used my Snap On 1/4" flex head ratchet and a 7mm deep to get all of them. For the 4 bolts that hold the heater core bracket in, I used an 8" extension with the same ratchet. Had the old core out in 45 mins.. Hardest part was getting the fittings through the firewall. Had a friend under the hood with a flashlight and a pair of long pliers to help guide them through the holes in the firewall. Once all was lined up, a firm push and everything was lined up. All in all, not a bad job. Book time calls for 3.5 hrs., I'll do them for that amount of $$$ all day long!

 

I'll be honest with ya, dont buy a heater core from places like Pepboys or Autozone. I had two fry and said hell with it, bypassed it after that. Well a friend of mine became partners in a radiator shop and I now have the Heater core to last a lifetime. I wish I could get more and sell em to the board but it was kind of a one shot deal. One of his guys recomended spending the money and going to a real parts store. On Long Island we have Roadside, which delivers parts to most shops in the area. Thats your best bet. O and leave the top screw out

 

Why does everyone dread that infamous "screw" on the top of the heater core housing? All it takes is a mini-ratchet, with a 9/32 socket. Sure, you're arm is in an awkward postition.... but it only takes about 1-2 minutes with the right tools.

For those who don't have the right tools, but have the time, simply take off you're Heater Box found in the engine bay.... there are two screws (one underneath, and one on the far right by the distributor), that hold the Heater 'Core' box on the inside in position. Once those screws are removed, as well as removing the retaining screws found underneath the carpet inside the car.... the plastic housing can be lowered/adjusted to easily reach that top screw.

But as far as Heater Cores go, I bought mine in Strauss 2 years ago, and so far so good.....