Here is the heater just taken out of the truck. Where to start? We have a few issues to consider. The two main issues are making it look like new and making it work like new. In this case it will be better than new since we will also use a 12 volt motor to run it. In addition, the unit must not in any way look as if it is not 100% original.
Let's get a few shots of the heater still fully assembled so that we don't forget how it goes back together. This picture shows not only how the ducts are arranged, but how much play in the defroster cable is normal. This will help during re-assembly.
This one will help us figure out the relationship of the parts during re-assembly. Once you have it apart, it becomes apparent how important the before pictures can be.
Here's a shot of the heater core and how it's installed in the housing. Turns out this core is good.
This is how the small duct housing is attached to the motor housing. In this picture and inside the main housing is a small rubber bumper. This picture shows the direction that bumper needs to be reinstalled in. You want to take great care and use unusual finesse in removing this bumper. It is not available through any of our vendors. It will need to be removed for the re-painting process. I realize this picture is too small to see it (Click on the picture for a larger one), but trust me, it's there, and you need to take great care with it.
This is how the two halves of the core housing are assembled. Just about everything involved in this project is fastened with #6 x 3/8 inch Phillips Pan Sheet Metal Screws. Buy new ones; they are cheap.
Here is the rest of the core housing removed from the motor housing. There were no gaskets in between the two.
This one is with the fan assembly removed. This is no big deal really. There is a slotted set screw on the side of the shaft and all it takes is loosening that and then a little persuasion with a punch and the fan will come right off. Be careful not to beat on things too hard since it is very possible to bend the fan assembly.
This is the entire heater disassembled. Not a lot to it, but these pics should help in getting it all correctly back together. In case you can't see enough detail, you can click on these pictures to make them much larger. They are in 1200x1600 high resolution.
This is to show a few things - what the Harrison Faceplate looks like exactly, what the 'motor to housing' gasket looks like, and the placement of the aforementioned rubber bumper.
There are two of them pesky rubber bumpers. Here is where the other one goes. Again, take care in removing them since they are not available new.
Here are all the parts laid out after sandblasting and thorough cleaning and then primered using a good self-etching primer. Take time to do a thorough job in prepping your metal parts. This heater will get hot and be used alot so the paint should adhere well.
My heater had a missing screen. Since I have two and can see what was original, I discovered that 1/4" hardware cloth available at the local lumber yard was what they used originally. I just got a small piece and then used JBWeld to glue it down. It was originally tack welded into place, but that would be a little hard for me to do. JBWeld works perfectly.
The one on the left is the 6 volt original and the one on the right is a 12 volt replacement. This difference would be noticeable under the hood thus unacceptable. It so happens that Chevs of the 40's sells a replacement 12 volt motor that is small enough to fit IN the 6 volt motor housing! It takes a little work to remove the 6 volt guts, but once you have done this, you have a perfectly original looking 12 volt motor.
This picture is offered so that you can get the correct replacement motor when you call Chevs of the 40's. They are also the only vendor I have found that has the complete gasket set for these heaters and the decal for the defroster mechanism. Bowtie Bits is the only vendor I have found that carries the thick rubber motor-to-housing gasket.