Heater rebuild

[pritch]

The heater in my green '68 barely works. I'm sure it's a combination of a bunch of crap like leaves and stuff plugging off the air flow and the heater core getting plugged off tubes. So I have been rebuilding a heater for it, and for good measure, one for my Panel project as well. I had most of 6 or 8 heaters laying around, so I started the process of finding the best ones. Most of the outer shells had that one corner broken off-the one that you can't get to the bolt for the fender being in the way. I made my decisions and went with this one and another that looked about the same:


After stripping everything off and a good scrubbing, I'll start with this:



There seems to be two different types of these. I think they changed at a year, but I don't know when. One has a metal ring inside that the fan attaches to, and the other has fiberglass nubs to take the screws. The one with the metal ring has the for pop rivets holding it on.



I say that the one with the metal ring is better. More on this later, but the other thing is, the later one, without the ring, has this blemish. A screw in the mold. 4 of the 6 I had had this. Good enough for O'l Green, but not for my Panel:

[GASoline71]

I've never seen anything like that (bolt in the mold). It's on the bottom part so no one will probably notice.

When I rebuilt the heater and core in my 1972 GMC, it had the metal ring in the housing.

Gary

[pritch]

After a little sandblasting and paint for the tin parts, reassembly:



These tin pieces are held on with 7 screws and 5 pop rivets. The rivets are aluminum and drill out easily. These screws have blunt ends, as they poke through on the outer side. I used some RTV silicon to seal the tin.

Next, work on cores. I had 4 decent cores, 3 of them re-pops:



I came up with this back yard cleaning system-a bucket, swamp cooler pump, some heater hose and harsh chemicals:





I ran this for 4 or 5 hours on the re-pops and a full 10 on the original. I think they came out pretty clean:

[54blackhornet]

What are you cleaning with ?
Posted via Mobile Device

[pritch]

One of the trickiest parts is putting the cores in. I bought 2 gasket sets and I dab a little RTV on in a few places to hold the core gasket on.





That particular core was only in use for about one winter, so I didn't think it needed cleaned. The orange RTV was from last time.

The little clips that hold them in only go one way-I think this is the reason some struggle with this part:





I start the top screws, then reach in and hold the core tight to the housing and attemp to start the bottom screws. These are the tough ones, but after a few tries, it's not to bad. On one of them, I had to use a longer screw to line up the hole. Don't run it in to far or it may hit the core.

Now, the fan motors. I had 3 originals and 3 repops. After testing them all, I decided that the originals run wayyy faster and stronger than the repops. I picked the best 2 and cleaned and painted them. Remember the fiberglass nubs for the screws? These WILL strip out easy if your not careful!



Remember to insure a good ground on the ground wire.

[pritch]

Finished. 2 just like new:







One last thing I'll do is get a very small paintbrush and paint all the screws and the little heat door tensioner thing.

Next time there is decent weather forecast for all weekend, I'll install the one for Ol' Green.

[pritch]

Originally Posted by 54blackhornet

What are you cleaning with ?
Posted via Mobile Device

A combination of about 1/3s of CLR, Napa radiator cleaner, and this vanitrol brand bowl cleaner that's like 25% hydrocloric acid. Probably not very good on the swamp cooler pump. Certainly not very good on bare skin or eyes. Be very careful!

[eldogg]

Looks Great! Thanks for the write up.

[BlacklandCamper]

+1 Huge help.

Need to do this before it gets cold.

[quick60]

Awsome thanks for documenting that.

Can you tell me what adhesive you used to secure the rubber boot that attaches to the the fan motor discharge and seals to the firewall? I used 3M spray adhesive and it didnt work very well.

Thanks nice work!!!!

[67chevemall]

Please show the install. How many hood bolts are you taking out? I am concerned my hood will not line up again if I take it off. I spent 5-6 hours lining it up all ready.

[slow-1]

Originally Posted by 67chevemall

Please show the install. How many hood bolts are you taking out? I am concerned my hood will not line up again if I take it off. I spent 5-6 hours lining it up all ready.

I just did mine, I only undid the passenger side hinge after marking it with a sharpie, it lined right back up.

Here's the thread:

http://67-72chevytrucks.com/vboard/s...d.php?t=600448

Wish I had seen this one before I did mine...lots of good info here.

[In The Ten Ring]

Can the thing be reassembled WITHOUT the rectangular gasket that attaches to the heater core itself?

Mine seems like it prefers not to have that. Is there a danger without that gasket being used?

[franken]

I read that the squarebody motor bolts in and runs way faster. The 67-72 originals were a mite slow...