AC/Heater Rebuild

[bigred88]

My heater core is leaking, my blend door tab is broken, my vents either face the floor or face the ceiling and are liable to change from one position to the other with each bump, and I pretty much only notice flow out of the vents with the blower on high because there are so many leaks along the way. And this is my dd- all in all it works well enough, but I'd like for it to be right. So the plan is:

New heater core
New blend door tab thingy
Stiffen the vents if possible/new vents if not
New gaskets/foam/tape all junctions

The heater core and blend door tab I've got covered.

As far as the vents go- does anyone know a way to keep them from just swinging down and facing the floor, or do I need to just buy new ones? I don't really care about the bright and shiny look of new ones (I think the new look would clash with the style I've got going on with the rest of the truck), I just want them to stay where I have them aimed at. Has anyone bought new ones? Who did you buy from, were you satisfied, etc?

And the gaskets/foam/seals/whatever you call them- does anyone know of a kit out there that would cover all of the under dash AC ducts? LMC sells them piecemeal, Cheyenne Pickup has kits, but only for up to a 72- not going to work for me. I'm not aware of any other vendors for this stuff- I'm sure they're out there, I'd be glad to hear your recommendations.

And I was thinking I'd tape over all the seals as a second barrier, but I have no clue what tape to use. Is there a specifc type of tape out there for this (and to the first smart ass that says duct tape...)? I'm looking for something that isn't going to dry up too quickly, and also that will not allow air to pass through.

Thanks!

 

[77k5blz]

My 77 k5 has the same problems its hard to adjust where to put the threaded rod on that (thingy) so u know its blending correctly. I hate to say it but duct tape could be used as seals for the tubing joints too. Im gonna do some research and ill let u know since were in the same boat.

 

[K5_Fla]

standard HVAC tape is what I used... works great.

 

[bigred88]

standard HVAC tape is what I used... works great.

I knew there had to be something like that out there, but I had no idea what to call it or what to even look for. That should work, thanks!

77k5blz- I've seen regular duct tape used under dashes before, and I've only ever seen it dried up, falling off, and leaving a bunch of nasty residue. That's why I'm hesitant to use it.

 

[82355]

There should be little foam pieces on the side of your vents. They have deteriorated, and that is why they flop around. You can shove a piece of paper in there for a temporary fix, or you can pop the vents out, and make something to take the place of the missing foam.

Martin

 

[herkdriver007]

Bigred, I wonder if some felt glued in would provide enough drag for the vents to not move...
Did you find a place to get the plastic blend door tab?

 

[bigred88]

Thanks for the replies on the vents. I'll have to pull one out and see what I can come up with for a fix. I really don't want to buy new ones, LMC wants $40 a piece.

Felt might not be a bad idea. I've got some left over random tape on insualting foam stuff that I bought at Autozone and used to pad my ashtray when I converted it into an iPod holder, so I think I'm going to see if that might work, but I have my doubts.

There's a few places I've seen to find the plastic tab- LMC lists them, as does Cheyenne, and I've seen links to other places I can't remember the names of when I did a search on here. I might be using a metal one from a member on here, but that isn't finalized, so if not I'll probably just buy a few plastic ones. They're only $3 each.

 

[herkdriver007]

Yea I was curious, classic has them for like 3, but another 8 for shipping

 

[goathearder]

I did this same thing to my 73 a while back and here a couple things I did to make it easier:

1) Butyl Tape at all seams (http://www.amazon.com/Butyl-Window-Flange-Camper-Sealant/dp/B0070O93HA). I was able to buy some at a local Camping World and I understand that most RV supply places have it. Works great and doesn't dry out. I took both sides of the air box off (inside and outside the firewall) and sealed both those pieces with the butyl tape as well.

2) Riv Nuts (nutserts) in the firewall. I found that the sheet metal screws holding the boxes to the firewall didn't hold super tight and were letting air leak out at the firewall. I drilled the holes out for 1/4-20 Riv Nuts to hold the boxes nice and tight. Between that and the butyl tape I have no more leaking at the firewall.

3) New Blend door tab - There is a thread on here where I designed a replacement in SolidWorks and I put the file up there so you could take that and have one made locally out of a much stronger material if you like. You can certainly buy re-pop ones too. In that thread, there are also a couple homeade suggestion if you want to try one of those.

4) Vents - I know this seems pretty ghetto but I use carb needles or dimes to "shim" the play out of the vents, works like a charm but looks kinda silly.

 

[itsacrazyasian]

I put dum dum tape on my vents to keep them from flopping around. Keeps just enough friction to stop the flop. Most parts store sell it, i know dorman does. Most places call it ac insulation tape.