Heater Box Rebuild

I’m in the process of rebuilding my ‘74 heater box. (Before and after cleaning of box pic included)
Is it ok to paint the box (fiberglass box) or should I leave as is?
I’ve cleaned and painted all the metal pieces.
Heater core, I’ve got the wrong one , of course, I’m thinking of heating and bending the outlet to match original. Thoughts... I read recent post on heater core and believe I saw someone said they had done this.

For new hoses, I saw a post for MTS ( MTS COMPANY, L.C. - Air boxes ) , thanks to timgr

 

Whether you paint is up to you. Might try a spot that won't show first then decide. There are paints that are meant for fiberglass and the like.

 

Rather than bend the heater core, you might solder elbows where needed to get the proper outlet location. Suspect that the copper tubing is not going to bend how you want it even if heated.

The original finish of the box is that flat gray color with some fibers showing through. It was not made of an expensive material. You might try some Armorall or 303 Protectant with buffing to restore close to the original appearance. Note you won't be able to paint over that treated surface.

 

Thanks guys. I will try the amorall / 303 first before paint and give an update later. There is a small triangular plastic piece (vent that connects to the bottom) I’ll try painting that and check the differences.
I’ll also keep looking for the right size heater core, so heating and bending or soldering will be a last step.

 

Like Timgr said, once you use the armorall or similar products paint won't stick or stay on. Make sure you do a small spot that won't be seen in case you decide to go a different direction.

 

Odds are good that it may not take paint anyway any oil or silicone will soak into in gellcosted glass. If you do decide to paint use a lot of pre-cleaner

 

Not sure why you wouldn't. I painted mine after a good cleaning. Tore it down re-sealed it. New core. My core fit perfectly. It turned out good. For this I used a rattle can Eastwood black low-gloss. I took it completely apart, soaked the metal parts in rust remover. Re-painted everything, sealed, assembled. New heater motor - 3wire type which was hard to find. Just installed it last weekend into the jeep. Only two pics I have of it.

 

I painted mine 10 years ago and it still looks great. I dont recall using anything special.

 

Looks like the box took the paint really good. How many coats? Any primer or just cleaned it really good? I used some maguires interior cleaner on it today and it got more dirt off. I think I’ll keep with the elbow grease until I feel it will take the paint as well as Chris’

 

Just a lot of soap and water cleaning, no primer on the box. But I did use a rust converter primer on the metal panels. I think I used maybe 3 light coats of black. One thing I didn't do that I should have. Was get new screws and the small clips. I forgot to get them, and ended up using my old which will work, but were in rough shape. I didn't worry to much about the inside. I guess time will tell...

 

Thanks Chris, et al, I’ll give an update when I’m done.

 

Thanks Chris for the unobstructed pics of the completed air box system as I will be doing my repairs on it soon. Alas, the original mil finish ( dust, dirt, grime) will remain somewhat intact.

 

I am currently rebuilding my 1974 CJ5 heater box as well. I have it all disassembled for cleaning and repair. The main "flap" located in the heater core are was covered with a foam that is available from McMaster-Carr (86225K53 - 1/4" foam) but I am not certain about the second defrost/heat flap as it is only the metal flap currently, no sign of any foam. Was this flap also covered with the same/similar foam?

Also there is a hole in the bottom of my fiber heater box that I am not certain if it is stock or was "modified" by the PO. I have attached a photo.

Another question is around the heater box drain pipe. Some of the TSM and part diagrams reference a rubber? hose attached, is this a specific part (ie molded etc) or was it just piece of rubber hose? where was it attached and where does it properly drain to?

Thank you all for any help/photos!

-Tim

 

The drain hose is a specific part, available today from Barney's
FITS JEEP CJ5 CJ6 AIR BOX 2 PC DRAIN HOSE 1972 - 1977 987079 NEW! | eBay

The connection is up under the dash, on the box that takes fresh air from the cowl. Not part of the heater. There is a hole in the floor for it.

 

Thanks for the reply Timgr but that is the drain for the airbox (under the cowl) and not the drain for the heater box that would drain in front of the firewall.

 

There was a molded rubber hose Jeep PN 975582 that originated from the 1/2"-ish drain tube that comes out next to the heater hose connections. Missing from my Jeep. I expect all it did was direct any rain water or heater core leakage downward to the ground. There is no aftermarket source for it today AFAIK.

 

Also, any hole that leaks air aside from the actual heat/defrost vents is not correct.

 

Is that "hole" I pictured in my original post correct or do I need to fix (fill) it?

 

A little better perspective (from further away) would help. Is that on the bottom of the heater? I would say yes, fix it. I don't think filler is what you need - instead something of a patch.

 

Here is a newer picture with better perspective. I know the two (yellow) holes need to be patched but the (red) opening/hole is the unknown. In looking at the operation of the heater box, if the flap is in the position where the defroster vents are blocked, then I am not sure where the heated air would go unless that (red) hole is in fact a floor type heat vent. What it looks like is that a PO probably cut the two (yellow) holes to let the heated air out on the floor more towards the driver?