HVAC Box, Heater Core, A/C Condenser Help

[jazz-n-tj]

So I am in the middle of replacing my heater core. Overall it has been going smoothly. But with most projects as I am finishing up the disassembly, I have run into some problems.

Upon pulling out the HVAC box and inspecting it, I have found multiple cracks in the plastic box and one that complete area that broke around one of the bolts that go into the firewall.

I thought I was going to get out of this project pretty cheap-$70 for a new heater core from Performance Radiators and $130 to evac and refill my AC.

I am thinking my only option is to purchase a new HVAC Box. From what I understand they changed after 98. The part number I have on my HVAC box is 55115210AD (see picture). The REV. E stand for Revision E (i.e., the 5th revision)?

I have found some used HVAC boxes for about $200. Since I am in there, I am thinking of getting a new AC evap condenser. I had originally thought I would not do it because the TJ only has 90k and it does not leak and the AC works great. I see the OEM Jeep condensers are about $350 and after market are $100-150. I am assuming it is worth the extra $200+ for the OEM.

I have thought about super gluing with baking soda the HVAC box. (I have had good luck with plastic using super glue/baking soda but I don't know how well it would hold up against all the vibrations and off roading I do in the Jeep.

So to recap I think I need:
-a new (used) HVAC Box-from what I have found online I can no longer purchase the box new.
-maybe a new AC condensor

I already have a new heater core and the OEM foam to put back on the HVAC Box to seal it to the firewall.

Any suggestions would be greatly appreciated.

 

[jazz-n-tj]

Sorry about the double post. It said it wasn't going through so I tried a second time and then both went through. @Chris please delete the other post. Thanks.

Also, I see that Performance Radiators has their own Evaporator Core for $70. Since I have heard good things about the heater cores on this forum, is it worth saving $250 and getting their evaporator. I don't want to be doing this job in the near future because it did not last. If the difference is $250, then it is worth going OEM.

 

[qslim]

I used the evaporator and the heater core from Performance this past spring. So far so good, but it's only been a few months so time will tell.

As for the box, I'd be looking for a replacement as well. You might get away with cleaning that plastic up & repairing it, but it'd suck to have to do that job twice.

 

[pagrey]

I'd fix it. Clean the box really well and get an aluminum plate that fits the areas with the cracks, thin like 1/16" plate. It doesn't have to be high grade or anything. Use a hole saw to cut out the section with the mount/drain on the repair plate. Get pop rivets and some JB weld clear. The epoxy dries a bit flexible and is great for plastics. Really roughen up the back of the aluminum plate and drill out holes in the aluminum so several go into each plastic section. Then use that as a template to drill the holes in the box, don't drill into anything important. Test to make sure it fits and the holes line up. Smear the whole thing with epoxy in all the cracks and on the plate and pop rivet it in place. The repair will be fine. I know not everybody is good with fabrication but I've done similar repairs and they work better than new.

 

[kmas0n]

What about one of those plastic repair tools...

https://www.amazon.com/dp/B0843BB4VK/?tag=wranglerorg-20

Anyone ever used one? Seems like the right tool for this job

 

[pagrey]

If you can't figure a way to reinforce where the bolt mounts I wouldn't try to repair it personally, like @qslim says, wouldn't want to do it twice.

 

[jazz-n-tj]

I think I am going to purchase a new box. I would be willing to try to repair it if it was easily accessible, but since it is such a big job to get to, I will just replace it to be safe.

Last question, what is everyone's opinion for the AC Evap.

1) Keep the one I got (91,xxx miles on it)
2) Replace it with Performance Radiator's ($70)
3) Replace it with OEM ($350)

 

[pagrey]

There's a member with experience in Arizona that posted in another thread recently about A/C, @Nimbley any thoughts on the evaporator? I'd go stock or OEM but there's no experience behind that, just what I might do in a similar situation.

 

[tr21triton]

I'd fix it. Clean the box really well and get an aluminum plate that fits the areas with the cracks, thin like 1/16" plate. It doesn't have to be high grade or anything. Use a hole saw to cut out the section with the mount/drain on the repair plate. Get pop rivets and some JB weld clear. The epoxy dries a bit flexible and is great for plastics. Really roughen up the back of the aluminum plate and drill out holes in the aluminum so several go into each plastic section. Then use that as a template to drill the holes in the box, don't drill into anything important. Test to make sure it fits and the holes line up. Smear the whole thing with epoxy in all the cracks and on the plate and pop rivet it in place. The repair will be fine. I know not everybody is good with fabrication but I've done similar repairs and they work better than new.

View attachment 275161

make sure you get the jbweld for abs plastic and get it to pop out flush, sand it good to scuff it up and coat it with the jbweld. i wouldn't use pop rivets because they will stop your blend door from moving

 

[pagrey]

make sure you get the jbweld for abs plastic and get it to pop out flush, sand it good to scuff it up and coat it with the jbweld. i wouldn't use pop rivets because they will stop your blend door from moving

I think he's getting a new box but you generally don't have to worry about blend doors on flat surfaces. Great advice to check what's behind there before drilling. I think they are different on some years but you can see the doors don't really scrub the back wall down where that mount is.

 

[tr21triton]

yea, being a aircraft sheet metal mechanic you learn fast to check twice before drilling. or you'll be doing 2 repairs instead of 1 or might drill your buddy's foot or hand (seen it done)

 

[4BY4ADV]

TBH... I'm a fan of the Harbor Freight plastic welder. You melt some metal mesh over the crack, then fill in the crack with plastic sticks.

I rolled a near brand new Yamaha Grizzly and opted to repair the plastic rather than spend $1,000 for new panels. It's held up for *years*.

 

[Nimbley]

I’d probably clean and check the old evap core out real good and keep it if it looked good…in my own vehicle. In a customer’s I’d recommend replacing it but give the option. If replacing it I’d buy OE if possible. They’re too much of a pain in the ass to replace if the aftermarket part fails. The money saved is not worth it to me.

 

[Viking Jeeper]

Is the evaporator available from Mopar? The heater core is not.