Removing a non-AC Heater Box

[bill70j]

I have done the research on this, including reading the threads on this Forum. Plus I have the FSM, so I think I'm ready to remove my Heater Box. I have a few questions and would appreciate your help.

I am the original owner of a '70 Challenger with the non-AC Box. It's never been removed, but yesterday it developed a huge leak while driving and the entire inventory of coolant ended up soaking the passenger side foot well. I'm wondering:

1) Should I remove the passenger seat?
2) Would it be worth the effort to remove the dash?
3) Any tips on dealing with the "J-Bolt"? I don't have a helper, except maybe my SO, if she's willing..
3) I don't know where the leak is, but I suspect it's at either the inlet tube-to-core joint or the outlet tube-to-core joint. What are the chances of being able to do the repair myself. Would it be a soft, or silver solder repair? Or should I just get a good-quality replacement core, especially considering it's the original core
4) The carpet and mat are a mess. Any tips on cleaning them up? And will that aroma ever go away?

Thanks for any and all input. I would appreciate it very much.

Bill

 

[floyd]

You will be able to remove the heater core without removing the dash. As with most under-dash related work, it will be easier if you remove the seat on that side. That will also help later with the carpet drying/cleaning process. Having a helper is good but it’s also possible to do it all on your own.

Since your heater core is original, I would recommend sending it out to Glen Ray to have it recored/repaired. Aftermarket cores are available at less cost but many people report fitment issues. Glen Ray does outstanding work so what you get back will be of higher quality than anything available in aftermarket. That will require more down time unfortunately.

I’ll leave it to others with experience to provide recommendations on cleaning the carpet. Thankfully I haven’t had a leak like that. Good luck, and be careful with the lower outlet vent on your heater box. It looks mint, which is rare!

 

[Steve340]

I took the glove box door and liner out of mine when I did it to help access/remove the control cables and wiring.
First job.
Disconnect battery.
Remove that kick panel/seat and get that carpet cleaned and lifted up from the floor sheet metal to dry out.
Maybe clean with one of those small carpet shampoo machines - otherwise the carpet will get a funny smell.

 

[Ronbo73]

I agree with floyd, try to have your original heater core repaired. The ones you buy now do not fit as well, you will have to adjust, when I say adjust I really mean bend, the tubes to fit where they should go. Worst of all, the tube lengths are shorter and do not stick into the engine department far enough for a regular sized hose clamp. I had to buy narrower hose clamps. Those are the problems that I had. I kicked myself in the a_ _ for not reusing my original.

Glycol in antifreeze takes a long time to dry if ever so I would use a pressure washer for soaking/rising, a stiff bristle brush and shampoo the crap out of the carpet. If you have the jute backing maybe just use your garden hose so you don't blast it away with the pressure washer.

Keep us posted on how you did it.

 

[terrywalker]

If the carpet is in great shape, I would remove both seats, console, seatbelts, the sill plates and kick panels, then remove the carpet and clean it outside of the car and let it dry in the sun. That's the best way to do it and not have mold/ mildew. Just my opinion.
Terry W.

 

[Challenger RTA]

The above advice is good.
1) Should I remove the passenger seat? YES!

2) Would it be worth the effort to remove the dash? No.

3) Any tips on dealing with the "J-Bolt"? I don't have a helper, except maybe my SO, if she's willing.. You have the right idea. Make sure the nut spins freely.

3) I don't know where the leak is, but I suspect it's at either the inlet tube-to-core joint or the outlet tube-to-core joint. What are the chances of being able to do the repair myself. Would it be a soft, or silver solder repair?
No. If I recall some are a honey comb epoxy type. At least mine was.

Or should I just get a good-quality replacement core, especially considering it's the original core.
Funny thing I did get one at Rock Auto a few years back an no problems.

4) The carpet and mat are a mess. Any tips on cleaning them up? And will that aroma ever go away?

Remove the carpet. then wet from the back and extract from the front, Carpet side .

La's Totally Awesome​

is a good cleaner apply it to the carpet side and work in as needed. Only use a little bit. Than extract as above. Detergent, dish soap any thing like that is an attractant for dirt. Don't use it. So for a finale rinse use cold water and a fabric softener. Helps knock down suds. Here again apply to the carpet side and extract from that side.
Side note. My information is from decades ago of installing and maintaining 2 dozen stores of laundry equipment. Also the same time running truck mounted carpet cleaning. My brother still does it. 39 years. Cleaning, mold, flood renovation. Yes It can be done with shop vac.

 

[Challenger RTA]

More Information for FOUR SEASONS 91508

 

[Steve340]

I purchased my replacement core from Mega Parts and it was a Modine - fitted and works great.

 

[tonysrt]

The biggest problem when the heater core is good is trying to remove the hoses. Trying to twist them off will sure cause a problem. I recently removed hoses on an old honda van but used a thin pick between the hose and the receiving mount metal and all came off easily. I did ruin my heater core on my 71 Cuda by not carefully removing the hoses, but back in the mid 80's a new one was only $30 and fit perfectly and now some 40 years old and leak free.

 

[Challenger RTA]

Trying to twist them off will sure cause a problem.

Try this when there is a problem. Make a 1/2" cut or more on each. Then work around it to loosen. A small sacrifice to save something of higher value. Or just cut the hose at the end.

 

[bill70j]

Every one of your guys' responses have been quite useful! So thanks to all - and please keep the responses coming if there are more. Based on what you have suggested so far, I will plan to:

1) Remove the seats, kick panels, door sills, shifter boot, seat belts, then the front carpet. I'll follow the advice for cleaning and drying the carpet.

2) Remove the glove box door and liner, all three door cables, j-bolt, the three nuts from the front of the firewall, then the heater box.

3) Once the box is out I'll look at the core damage and decide what to do next. Yesterday I called Glen-Ray and they were quite helpful. I'll probably send it to them for repair, although a new core sounds like a possibility.

I'll document this process in case it might be useful for someone in the future.

Here's how I think I got myself into this mess: For a decade I've been adding coolant resulting from some obvious leaks (laziness). Finally last week I decided to fix it all.

So I bought a new Milodon pump, pulled the radiator and polished all hose connection points. Put the system back together, built a pressure tester and did a pneumatic test. It held steady at 16psi, but there was a very small leak somewhere causing a slow bleed-down. I did the bubble test at all the connections (except the interior heater core). No visible leaks, so I filled the system with water and ran the engine for an hour. No leaks, including at the heater box. (BUT, there was a small patch of condensation just above the passenger side dash, which I blew off.) So I drained the water and charged the system with a 50:50 mix. Then on a second test drive disaster struck.

With tight connections everywhere, I suppose the heater core was a weak link in the system. I have a strong suspicion that I did the damage to the heater core - those hoses were a b*tch to get off, so I finally had to slit both of the hoses at the firewall - and wasn't too gentle in the process. Lesson learned.

Thanks again, Bill

35 yr. Old Water Pump - Source of Several Leaks




Pressure Tester Using Scavenged Parts From HFT Fuel Pressure Tester

 

[bill70j]

Try this when there is a problem. Make a 1/2" cut or more on each. Then work around it to loosen. A small sacrifice to save something of higher value. Or just cut the hose at the end.

I just posted - a few seconds after your last post. You nailed it.

 

[Finoke]

I used a J hook bolt that was a half inch longer for my last heater box install. I also have a tool box that is almost the same height of the heater box. So I stick that under the box for removal and install. So you are not trying to muscle it in and out.