the dreaded heater core

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Groping the heater core inlet, (the one that leaks) there's a dent in the pipe. I am sometimes that lucky. We'll see - hoses on!

Tried to swage the dent out of the heater core inlet pipe, but didn't have the room to get it all out...yet. Have to remove the rocker cover for better access and see if I can get more of it out, "rounding" the outside of the pipe with epoxy to get a good seal on the hose.

 
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Nope. Heater core started to leak inside. Not all that bad getting the box out and the core removed. Getting it back in will be the fun part. It only leaked for about 20 seconds, so no damage to carpet, minimal gasket or firewall damage or evidence. Can't imagine it hurts to have one more perspective on the job, so I'll add my own simple version. The others helped. maybe this one will help someone else who reads here.

Short version of EX-tallation:

0. Look at the previous manual pages posted by MechEng, and look at the pictures, and read the section on removing the box. You won't "have to" do all it says, but it will help you doing this list.

0.1 remove glove box door and box and take many pictures front, and to the right and left, for reference later.

0.2 remove kick panel

0.3 Pull back carpet - more space, less water damage.

1. Remove hoses from inside firewall and remove two nuts on the studs near them that hold the box to the firewall.

2. Remove hose from under heater box that goes though the lower firewall.

3. Remove vacuum hoses and actuator cables from the small motor mounted on the box next to the bottom of the dash

4. remove that small motor (2 screws) push it out of the way of the box.

5. Pry off the several clips. There is one on the left and one in the back that you may not or won't see, but you will know they are there. (I didn't tell you, like the manual does) to remove the bolt that holds the top of the box to the dash with a short metal strap because I did, and in order to do it this way, I put the screw back in place to hold the top of the box and A/C core up and out of the way.)

6. Pull the box slightly out from the firewall - since you didn't remove the AC hoses in the firewall, you'll only be able to pull it in an inch or two...it's just enough.

7. If you pull the after market radio out, (or remove the center lower dash panel if stock) you can remove the right one of the two bolts/screws holding the plastic blower tube in place to get just enough room to scootch the bottom of the box out. (not necessary to loosen the blower motor like the manual says, couldn't find the two screws the manual talks about with the box in place anyway.

8. If you have done these things, you will be able to carefully pry the bottom away from the top slightly, to insure you have all the clips out, and begin to scotch/pry/wedge/tilt/wiggle/pull/push/do not yank, do not pull hard but maybe firmly, and voila, the bottom of the box comes out with the core in it, and leaves most of the rest in place.

9. Bottom of the box out of the car, remove the screws holding the doors/flaps in place, remove it, and then pull out the core.

From there, remove the foam gaskets slowly and carefully, pry lightly with a flat blade if necessary and don't tear them. I blew some air through the core underwater to see where it failed (unnecessary, but fun for my wife to watch me get a little soaked). My gaskets are in pretty good shape, but your mileage may vary...prepare to wait for new ones.

Depending on how long it takes and if there are any "tricks" to getting it back together, I may add an installation task list. Don't count on it. ;)

 
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Last time I changed the heater core on the Grandé, I was thinking I won't do it again.

But as I want to check all heater system while the car is empty, I start to do it again on the Mach1.

But here I have AC, which I won't use again.

So in this case, should I keep all hoses connected and the AC switch too?

Anyway I think it's not a bad idea to check how looks like the heater core.

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In reading through all of the pain everyone has had with heater cores I did not see where anyone tested the core before installing. I installed one in an Econoline van that required that the entire dash come out. Got it all back together and going in one day. Started it up and the D&%$ new core had a leak in it. I took it back out and put in water with air pressure, 15 lbs. and it bubbled from inside the core so I had not punctured it. Of course they replaced it but all the pain of doing it again. 4 hours the second time.

So when I already had the dash out of my 73 convertible I pulled the heater box and did a restore on it. I got a NOS core off eBay and this time I tested it and low and behold there was a leak. It was a big blow up trying to return on the eBay item so I just went to Auto Zone and got one there and tested it with 15 lbs. air pressure in tank of water and no leaks.

We all know the gasket or seal kits they sell suck and you have to make some of your own. Another good reason to pull the heater is to get all the trash out, leaves, pine nettles, acorns, mouse nests, etc. in there. I also recommend that you put a piece of 1/4" box wire over the air intake coming from the cowl to prevent the critters from getting back in.

It is not really a bad job but I do recommend you pull the entire dash and you can clean up the insulation that the factory puts on the cowl and replace with some stick on foam. It is also a good time to replace the firewall insulation matt and the insulation behind the kick panels.

David

 
Sure it helps to remove the dash, what I almost did, just remove a few bolts on the passenger side dash, and this gave me a little bit room to remove the box.

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Should I remove the evaporator since I delete the AC?

 
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Sure it helps to remove the dash, what I almost did, just remove a few bolts on the passenger side dash, and this gave me a little bit room to remove the box.

Should I remove the evaporator since I delete the AC?
The airflow through the heater box will not work correct with things missing. I am not sure if it will work right or not. Someone on here might have done this previous and can tell you.

Why are you removing a desirable option like Air? Even if you do not put the belt on it adds value if you ever sell.

David

 
I maybe should maybe open a new thread for that, sure there are some guys who moved from AC to non AC.

If it does make an air flow problem without the evaporator, I will leave it inside the box.

 
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I've gotten so tired of the damn things, I have looped the hose in the engine compartment and drive it without heat, bypassing the booger. They are not my only cars, so I don't mind wrapping up when I drive them. Kinda like riding a motorcycle. lol

 
I maybe should maybe open a new thread for that, sure there are some guys who moved from AC to non AC.

If it does make an air flow problem without the evaporator, I will leave it inside the box.
To replace the air conditioner heater box with no air is more work. There is a helmet shaped part in the firewall that is not on air cars. It clears the blower motor. The ducts are also different under the dash and you do not have the opening on the left side for fresh air from the cowl. I would rebuild your heater that has air and just put it back in will save you lots of work. I attached a picture of a no air car firewall and the helmet part on firewall. Also an air car firewall and same area where the helmet piece is on no air.

This topic needs a really good thread so many are afraid to take the heater box out because they do not know. It is not difficult and you can do in one Saturday unless you are going to take the heater box apart and do a full restore. It is just screws and nuts and clips not rocket science.

David

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