[SNitro]

I removed the hvac unit for a heater core replacement and found that one of the air directing find is just coated in tar or some sealant.... any ideas? Has anyone else seen this? I have noted in the past that hot air ALWAYS came out of the defrost vent regardless of the chosen setting.
Is this the cause for that issue? It's not factory proceedure to tar something closed

is it?

 

[SNitro]

Looks like it's a rubber seal that had a chemical reaction maybe? Or just poor chemical make up of the rubber.... it melted into a tar like substance. Plastic gear that is attached mechanically to this fin has stripped its gear teeth (defrost fin gear). (Side effect to gear stripped... air will always be shared with defrost.)
This is the only one that melted like this. The other fins with rubber seals are intact and strong.


Heater core now installed in hvac system and I've begun reassembling... wish me luck!

 

[Scar0]

Yep, that sounds like just the case. Melted seal. We have had another member find the same when they only had heat out the defrost.

 

[cmm47172]

Looks like it's a rubber seal that had a chemical reaction maybe?

So, what did you do to fix it?

 

[Amorris0013]

I did a write up previously about my experience with the same problem. I purchased a new hvac distribution box and seals kit on Amazon (total 200ish). There was no salvaging the original with the tar like material on it. Snapped the entire gear on mine. I'd just get a new one.

 

[cmm47172]

I did a write up previously about my experience with the same problem.

Thanks for your reply. I would like to read your write up but can't seem to find it. This is an awful design. You can replace the part then have to go after it again years down the road. I've seen videos on doing the job and it looks frightful. I have a 67 GTO that I restored from the ground up inside and out I had it completed gutted inside. It was a chore and a half but it was not as bad as what the dodge dash removal looks like. I keep having a debate with myself over whether or not I should replacing the heater core and AC evaporator while I have it torn down. I have nothing wrong with those things right now but I would kick myself if I start having trouble down the road with a leak or something and then have to tear into it all over again. Did you replace those things yourself when you did the job? How did you recover the refrigerant? That will be a tough part of the job for me. Not having the equipment to do a recovery or pull a vacuum on it and refilling the refrigerant after all is back together. I got an estimate from my dealer. To replace the HVAC box they want $1,225 for parts and labor. If I have them replace the heater core and evaporator as well they will do the entire job for $2,925.00. That a serious amount of money. Not sure what I should do at this point. I keep reading about this and posting questions all over the internet trying to build my confidence up in doing the job. To make things worse, this is my wife's car and she will have a fit if she has to be without for more than 3 days. They say the job takes about 8-10 hours. At the rate I work, being very careful, slow and methodical, I know this will take me at least a week.

 

[Amorris0013]

This is my previous post

"As a follow up long overdue, I can say that I have successfully replaced the HVAC distribution box with Heater core as well. As someone with relatively little experience working on vehicles, this was byfbar my biggest undertaking. However, following a YouTube video made it actually fairly easy to do. Start to finish was about 6 hours of work for me.

What I found was similar to what was mentioned above (see picture below), my seals had basically turned into a black, tar-like material that prevented the actuators from being able to turn and open the associated doors. It required me replacing the distribution box to fix it, no other way around it. I found the hvac box on Amazon for roughly 160 bucks and got a heater core for about 70. You need to purchase replacement seals which were also on Amazon for 25 bucks. All said and done with a few extra tools I got to make my life easier, I had it repaired for under 300 total.

This is the video I used to guide me,

it was spot on with everything. Take the time to stay organized, using the box for bolts was a good idea. Supposedly there's a way to make it so you can pull the handbrake lever up without actually engaging it (if you're worried it's rusted and won't release after pulling it) but I couldn't get that to work. I didn't have to disconnect the AC lines nor empty the coolant, you can separate the hvac box from the AC housing once the dash is down.

All in all, it's a big project and can be intimidating, but following the video along makes it manageable. Just block off a couple days to make sure it can get done and you're able to move at a comfortable pace."

 

[cmm47172]

Thank yo so much for your reply.
Sorry for all the questions but you seem like you really know what you are talking about.
What year is your Nitro?
Mine is a 2009 Didge Nitro SLT 4X4 (LHD).
I really like your idea of not disconnecting the AC lines.
I hope that's doable on mine because I don't have the tools/knowhow to pull a vacuum on the AC system afterwards in order to recharge the refrigerant.
What replacement seals are you referring to?
Are you talking about the foam rubber around the air outlets?
Did you pull the dash completely out of the car or did you lay it across the seat like the guy in your video did?
I found this video...

This guy disconnected the wiring under the hood and pulled it thru the fire wall on the passenger side thus allowing him to remove the dash from the car entirely.
I'm thinking that would make it easier to remove the distribution box at that point but not sure its worth the effort.
Also, in my guy's video at 24:30 minutes in, he split the distribution box in half to remove the heater core.
Did you have to do that or did you pull it out from the side like your video showed?
Also, in my guy's video at 22:35 munities in, he had to pull back the drivers side carpet to get at a ground wire.
Did you have to do that?
Lastly, in my video, he didn't take the shifter out.
Did you find it necessary to remove the shifter?
I appreciate anyone's input on this.

 

[Amorris0013]

Thank yo so much for your reply.
Sorry for all the questions but you seem like you really know what you are talking about.
What year is your Nitro?
Mine is a 2009 Didge Nitro SLT 4X4 (LHD).
I really like your idea of not disconnecting the AC lines.
I hope that's doable on mine because I don't have the tools/knowhow to pull a vacuum on the AC system afterwards in order to recharge the refrigerant.
What replacement seals are you referring to?
Are you talking about the foam rubber around the air outlets?
Did you pull the dash completely out of the car or did you lay it across the seat like the guy in your video did?
I found this video...

This guy disconnected the wiring under the hood and pulled it thru the fire wall on the passenger side thus allowing him to remove the dash from the car entirely.
I'm thinking that would make it easier to remove the distribution box at that point but not sure its worth the effort.
Also, in my guy's video at 24:30 minutes in, he split the distribution box in half to remove the heater core.
Did you have to do that or did you pull it out from the side like your video showed?
Also, in my guy's video at 22:35 munities in, he had to pull back the drivers side carpet to get at a ground wire.
Did you have to do that?
Lastly, in my video, he didn't take the shifter out.
Did you find it necessary to remove the shifter?
I appreciate anyone's input on this.

I followed the video I sent you pretty much step for step. My vehicle is an 08 SXT. For the seals, yes they are the foam ones around the vents themselves. I did not disconnect the wiring from within the engine bay, I only pulled the dash onto the front seat for that reason, it made it more difficult to get the distribution box out but didn't want to pull the wiring harness entirely instead. I did not have to split the hvac distribution box, mine pulled out from the side. I did not have to pull the carpet, either. I pulled the shifter, it wasn't difficult, but it was necessary for me to pull the dash onto the front seat.

 

[cmm47172]

I followed the video I sent you pretty much step for step. My vehicle is an 08 SXT. For the seals, yes they are the foam ones around the vents themselves. I did not disconnect the wiring from within the engine bay, I only pulled the dash onto the front seat for that reason, it made it more difficult to get the distribution box out but didn't want to pull the wiring harness entirely instead. I did not have to split the hvac distribution box, mine pulled out from the side. I did not have to pull the carpet, either. I pulled the shifter, it wasn't difficult, but it was necessary for me to pull the dash onto the front seat.

I just found another video that was a follow up to the one I mentioned.

Check this out at 1:30 seconds in. Did you have this happen to you?
The guy was having an issue getting the dash out and broke it because it was hanging on the steering column support bracket.
I'm thinking he could have loosened or removed the bracket.
Did you run into that issue?
Also do you have a part number for the foam seals by chance?
Thanks again!

 

[Amorris0013]

I just found another video that was a follow up to the one I mentioned.

Check this out at 1:30 seconds in. Did you have this happen to you?
The guy was having an issue getting the dash out and broke it because it was hanging on the steering column support bracket.
I'm thinking he could have loosened or removed the bracket.
Did you run into that issue?
Also do you have a part number for the foam seals by chance?
Thanks again!

I did not have any issue with the steering bracket, mine did not get stuck at all. For the seals, this is the part number, 68003995AA. Available from Amazon. Comes as a kit, I didn't use most of it but it has the one seal you will need.

 

[cmm47172]

I did not have any issue with the steering bracket, mine did not get stuck at all. For the seals, this is the part number, 68003995AA. Available from Amazon. Comes as a kit, I didn't use most of it but it has the one seal you will need.

Thanks again for your insight. Much appreciated. I'm still debating whether or not to do this myself. I have to make a decision soon. I will post a follow up.

 

[Amorris0013]

Thanks again for your insight. Much appreciated. I'm still debating whether or not to do this myself. I have to make a decision soon. I will post a follow up.

Honestly it was not as bad as it seems from the start. I followed the video I linked from start to finish. Took me about 8 hours total time to do the project with some breaks. Just give yourself a couple days and stay organized, if I could do it I'm sure anyone else could, too!