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Need help replacing the heater core

2K views 12 replies 6 participants last post by  68RCodeConv 
#1 ·
The core in my '68 has started to leak badly. I was told the dash needs to be removed, is this correct? Any steps, guides, tips, or pointers would be greatly appreciated. I don't want to pay the $200-$400 labor unless I find out it's more work than I can fit into my schedule.
 
G
#2 ·
if you can remove your glovebox without removing your whole dash, your in business. Just be VERY careful removing the core itself. I recommend carefully cutting the hoses lengthwise to remove and replacing them(if you are leaking they are probably full of rust) I had to do this on a later model 84 and it was easy but tedious work. I will look into this with a freind who restores mustangs and see what he has to say. Back with a more precise answer this weekend.
 
#3 ·
I have the glove box out now, well the inner shell at least. the front side of the heater box that's clipped on seems to come out fairly easy, but I'm not sure where / what holds the rest of the unit in place. I can access the two large heater hoses that connect at the back of the core, what would I actually be cutting? Don't they just unscrew and pull out or are you talking about something else?
 
#4 ·
This is not that difficult of a job. But if you are going to it make sure you rebuild the box at the same time. Get the new seal kit and new plenum. You would be best to pull the right side panel from the dash so you can get to things easily. Disconnect the heater hoses at the block. Pull the four nuts off the fan on the engine side. Disconnect the box where it connects to the dash. Then disconnect the heater cables. This is a good time to replace those cables also. While it sounds like a big job, you can do it easily one one day. Buy paint for the box, some spray on contact glue and the new seal kit. You will appreciate the additional heat soo much. Replace the hoses and make sure you are routing them correctly. Lots of WhileIamit's but while your there you should do those steps. Flush the radiator system while the hoses are off you do not want gunk fillin up the new core either. Sorry its somewhat disorganized but I think you can fit it together.
 
#6 ·
Yes the engine hoses go directly to that core. If you can get to it then you can do a quick replacement. You will have to unclip the front of the box there are 6-8 clips. Be careful pulling the clips off if you do it incorrectly you will chip or split your box and ruin either the front or the back. Thats why its easier to pull the box out of the car and do this on the bench. Do a search on the web and you will find one that shows you the correct way for removing these clips. Prying them off with a screwdriver against the box will certainly cause you problems. I believe you are suppose to fulcrum the screwdriver on the clip to release it. If you do pull the box also make sure you reach up into the hat and clean out the cowl of any debris.
 
#7 ·
Listen to the previous poster. It really is the right way to do it. If you have air conditioning it is a much tougher job. Without a/c it really is an easy job and can be done easily. Once you have done it once you can do the whole remove and replace in a couple of hours.
 
#8 ·
The dash does not need to come out. The heater box behind the dash does need to come out to access the core. If you have factory in dash A/C, the process is more involved as the A/C needs to be disconnected under the hood to get the heater box out. With no A/C, removing the glove box should give you the access you need to pull the heater box.
As an aside, you can disconnect the heater core from the heater hoses under the hood, and re-route the heater hose back to the engine, bypassing the leaky core, thus giving you the opportunity to drive the car (without further leaking problems) until you find the time (and $$) to have the repair made.
 
G
#9 ·
I would definitely go the long route ms has described. The reason I cut my hoses was to facilitate and easy removal as I bought new hardware for the new core. The problem with prying at the rings or pulling hard on the hoses is that the core is brass and therfore bends or splits easily. Flushing the radiator is a great idea(I am slow today lol) as you need to remove deposits anytime you do something that is connected to it. Good luck and that is a fine looking stang you have there.
 
#10 ·
I'm having trouble disconnecting the hoses from the core itself (I am attempting to do it without removing the whole heater box). I have given up on this idea and want to remove the box totally so that I have better access to the hoses. Where are the bolts that hold the rear half of the heater box into the car? I see 4 bolts surrounding the fan inside the engine compartment but I am not sure if these are the ones holding the box on. Any help would be appreciated.
 
#11 ·
I would recommend cutting the hoses on the engine side (keeps the anti freeze out of you car), then pull them through the box. You can get new hoses at the AutoZone.

It is virtually impossible to pull the hoses off the core while it is still in the car (note, you will also want to put the hoses back on the core and run it through the back of the box and firewall before putting the core in the box).

It really isn't that hard to get the whole box out if it's anything like a 66.
 
#12 ·
Yes Adam, those four nuts surrounding the fan are holding the heater box to the firewall. Once you unbolt those the box will be loose. Make sure you have it completely disconnected on the inside from the dash and the cables. Then from the inside, jar the box back and forth pulling it towards you. Have someone on the outside watching the disconnected hoses as you pull the box. The hoses can get tangled and give you trouble. As you get to the end of the hoses reach in and pull them up so that no anti-freeze gets in the car. Take the box to the work bench and remove the heater hoses and unclip the clips from the box. Make sure you do not pry on the clips!!!! Then the box will be open and you will see the core. You will likely see all this dust and foam around the inside that is the seals that used to be there. This is why you need to rebuild it with new seals. The seal kit is like $11.00 Paint another $5 and the core will cost you around $40. A new plastic plenum is like $25. Cables can be around $40. If you need to save up some dough then connect the hoses from the intake to the water pump and run the car like that until you have the funds.
 
#13 ·
Use a 1968 heater core when you buy a new one. It has extra long hose connections that actually extend through the firewall so that you can attach the hoses in the engine compartment. This was a running change Ford made sometime in 1968.
 
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