winter brings me to doing interior freshening. one area needing attention was defrost duct. downright nasty when cleaning windshield and looking down in. so while i'm upgrading radio and some other dash items i started removal of the V duct. due to the dash brace i'm stumped. have heater cover off that didn't help. am i going to have to remove heater box to be able to remove this duct for clean up ? i can see dirty broken cork gaskets but just can't get it past the dash brace or out of the heater box.it loose but won't pop out.. HELP PLEASE ! thanks, Dennis

It's been a number of years since I did mine and my car has factory A/C, but I don't think you will be able to pull the Y duct without removing the heater box.

I just reassembled my ducting (and forgot the y duct the first time I tried it :clonk: ). Trust me when I tell you, you cannot get the y duct in with the heater box installed. Ask me how I know. The heater box is easy to remove anyway, so you might as well go ahead and take it out and replace all the seals at once. If your defroster seals are bad, I'm sure the others are just the same. Our sponsor (Ground Up) has a kit for about $15 that includes all the seals you will need. It made a big difference on my car.

thanks for the reply. i was afraid of that. but seemed like only route left to try. is that just removing the 5 speed nuts on the firwall.? or is it necessary to drain radiator and inner frnder on some threads i've read ? thanks again as i can't tell from ***. manual.
dennis

You don't need to drop the inner fender unless you're doing the blower fan, but you will need to drain the radiator and pull the hoses off the heater core (unless you have a few extra feet of heater hose). The core is attached to the box and will need to pull away with it.

Yes, the 5 sheetmetal nuts on the firewall are what holds the box in place. The cover on the engine side will stay in place with all those off, because it has a couple of bolts out under the fender.

You'll want the box off anyway, because the seal kit you buy to get the y-duct to dash seals has all the heater box seals in it too, so you might as well do them too. It will be a bit of a pain to get the inner heater box seals in place without drilling all the spot welds out and opening the box, but with good adhesive, some dexterity and some bent coathangers to get them in place, it can be done.

Might as well have the heater core tested while it's out.

This is one of those projects that doesn't cost too much, but takes some time and will give you a skinned knuckle or two. It's worth it to have everything sealed up and working right though. Defrost works better when the box seals are good and it isn't blowing out under the dash top.

And yes, that is a giant snowball you hear rolling right at you...do something simple like try to reseal a heater duct, next thing you know your car is gutted. :)

Eric, thanks for the in depth reply. better to know where i'm headed than to just be taking parts off. yes its getting gutted in there and as always one project leads to another. thanks and a happy new year. you know where i'll be !
Dennis

Dennis,
I'm with you on this one...another thing to add to your shopping list might be a new firewall pad. Once I got everything out yesterday, I noticed it got tore up while removing the heater box.
Scott

thanks scott i had that item on my possible list and was going to remove it if the heater box did not have to come out but now what the heck. may as well do it all. thanks
dennis

Hey Eric, what a bear ! first that 5th nut closet to the fender presented a little challenge. but nothing like getting those cabels diconected and removal of the heater box. i'm either a real slow learner or shouldn't be doing this kind of work because i struggled geting the Y defroster duct out even when the heater box was removed. my wife keeps asking are you going to be able to get it back together ? i say no problem i have a friend on the internet whos coming over for one of your home made pasta dinners after we put it back together or check the classified ads for a 69 big block parts car. exterior compledted just needs interior put back together. again thank for the info.
Dennis

Dang it, I knew I forgot to tell you something...

If you can disconnect the cables at the control in the dash (after labeling them, of course), it makes life easier.

And yes, it is a pain. I never had the Y-duct out of my 67 or 68, so when I started reassembling the 69, I put the box in first, got it all sealed up nice. Two months later I tried to put the duct in and after gyrating with it for 10 minutes, knew what I had to do. Good thing I hadn't filled the system with coolant yet, but it was still a pain.

Be careful not to break the duct putting it back in. I broke one once at the lower brkt. Those things are a little brittle being so old.

lol...so did I. A little JBWeld did the trick.

Be careful not to break the duct putting it back in. I broke one once at the lower brkt. Those things are a little brittle being so old.

hi i am pretty much finished putting the interior back in and i gutted it before paint but if you have gone as far as removing the heater box would you consider installing a after market a/c system .unless your keeping it original i just put in a vintage air its a sweet system you can throw the defrost duct out but your half way there now just a thought Tony

Thanks Tony, my original thoughts were to do a vintage air but then i decided to go the route of an L89 clone since it was a big block car when i purchased it. some day it may wind up being an air car and if it does it will be a lot easier the second time around doing this major gutting. awaiting firewall pad and heater box gaskets to start reassembly and a couple more cans of interior dye to complete some sprucing up. thanks for the advice.
Dennis

Thanks Tony, my original thoughts were to do a vintage air but then i decided to go the route of an L89 clone since it was a big block car when i purchased it. some day it may wind up being an air car and if it does it will be a lot easier the second time around doing this major gutting. awaiting firewall pad and heater box gaskets to start reassembly and a couple more cans of interior dye to complete some sprucing up. thanks for the advice.
Dennis