Replacing Defrost Hoses for 1971 Demon

-

Rob Di Valentin

Demon 340
Joined
Dec 17, 2016
Messages
44
Reaction score
14
Location
Ontario
I have new hoses to replace the make shift set up that's currently in there. Is there an easy way to do this get to the vents? Do the vents pop out from the top? Undo the dash? This is a pic of the passenger side defrost hose with the glove box removed. ( sorry for the upside down photo)
defrost hose (002).jpg
 
I have new hoses to replace the make shift set up that's currently in there. Is there an easy way to do this get to the vents? Do the vents pop out from the top? Undo the dash? This is a pic of the passenger side defrost hose with the glove box removed. ( sorry for the upside down photo)
View attachment 1715144076


What replacement hosed do you have? Pics?
 
Wouldn't it be nice if those vents popped out, hose shoved in from top down? Sadly that's not the case. There isn't a easy way. Pull the glove box liner helps access the right side vent.
I did purchase the reproduction kit from DMT. It aint OEM perfect reproduction but does include the adapter for different hose port diameters ma mopar cursed us with.
 
Gonna try using new shop vac hoses like described in "318willruns" post

Go to your local Napa Dealer and ask for the 2" and 2.5" heater box hose. Its sold in 6ft lengths so you will have to cut it to proper length but is much cheaper, installs much easier and looks very correct for Mopar A-bodies. I bought the DMT kit and it didn't fit well at all. Here's some pics of the DMT kit. As you can see, its impossible to slide the hoses over the heater box outlets with the Adapters in place as both hoses I received were the same diameter. Note: I was installing the DMT kit on a 68 Cuda. Not sure but I believe the heater box is the same as your Demon.

Here are pics I took of the DMT kit I tried to install as well as pics of what the originals looked like installed. Note the clearance differences between the originals when installed vs the DMT hoses. Its impossible to install both DMT hoses at the heater outlet the same time.

Note: I contacted DMT and they did give me a partial refund . I have dealt with this company for most of my gaskets and insulation products and with this exception, they have been first rate and very good to deal with!!

DSCN4873.JPG
DSCN4877.JPG
DSCN4878.JPG
DSCN4879.JPG
DSCN4881.JPG
DSCN4882.JPG
DSCN4887.JPG
DSCN4888.JPG
DSCN4889.JPG
DSCN4890.JPG
DSCN4891.JPG
DSCN4892.JPG
 
Shop vac hoses?

It takes a little adapting for the smaller defrost outlet on the heater box, but it looks good and works.
Not nearly as expensive either.
I used weatherstrip adhesive to attach to the vents and box.
About 20 bucks at Home Depot, and you can cut the extra end adapters for spacers if you wish.
A heat gun helps make the curves from the box up to the vents nice and tight if you wish.

ridgid.jpg
 
I didn't use the thinner walled adapter. I don't recall if maybe I put a zip tie over than hose ( Its been a while ). The thicker walled adapter was req'd. In the end its better that anything else I had tried over the years.
 
I didn't use the thinner walled adapter. I don't recall if maybe I put a zip tie over than hose ( Its been a while ). The thicker walled adapter was req'd. In the end its better that anything else I had tried over the years.


Yup! That's the only way that kit works. Leave out one of the adapters but, then you lose air flow through the sloppy connection to the windshield vents.
Out of desperation one night I got on Nappa's website and after looking over the options for heater box hoses, I found the 2" and 2.5 " on their site. I ordered them in (6 ft lengths available only) and received enough to easily do two cars for less than the kit from DMT. Best part was I shared the cost with one of my friends and the hoses installed perfectly. Just had to use a little white grease on the hose ends to make it easier to install.
 
Yup! That's the only way that kit works. Leave out one of the adapters but, then you lose air flow through the sloppy connection to the windshield vents.
Out of desperation one night I got on Nappa's website and after looking over the options for heater box hoses, I found the 2" and 2.5 " on their site. I ordered them in (6 ft lengths available only) and received enough to easily do two cars for less than the kit from DMT. Best part was I shared the cost with one of my friends and the hoses installed perfectly. Just had to use a little white grease on the hose ends to make it easier to install.

So how did you physically get to the vents? Was the dash apart? Were the vents out of the car?
 
So how did you physically get to the vents? Was the dash apart? Were the vents out of the car?

In the pics with the measurements shown, the entire dash was out of the car including the heater box. I pre assembled everything before installing the dash to make sure everything would go back together ok. This is where I found the problem with the DMT kit.
After getting the proper type hose from Nappa, I was able to reinstall the dash and heater box , then just reach up under the dash to install the hoses onto the vents. Just used a little white grease around the edges of the hose and they slid into place. Completed the job in a few minutes actually!!
 
Not to bash on the OP or anyone else in this thread but I've never understood why people have so much trouble with the defrost hoses.

First, you want a material that's flexible and not heavy. I can't tell for sure but the pics look like a heavy rubber type hose - not ideal.

Second, don't bother with adapters. There's not enough room for them and they cause more trouble than their worth.

Third, prepare to get creative with how to attach the hoses to the heater box as well as the defrost vents.

Here's what I did on my '71 Dart 13 years ago. Look online for some hoses with the correct ID to go over the heater box fittings without adapters. As other posts in this thread show they are different diameters. I found mine on ebay, generic hose ducting. Buy some length of that hose. Make sure the hose is flexible or can be formed from using a heat gun. I attached those hoses to my heater box with big zip ties, 1 on each, pulled tight with a pair of pliers. The factory clips for attaching the hose are nice if they're in good shape. You could also use duct tape (black color) if done correctly with a good brand of tape. Another option is going to the hardware store and looking and different types of radiator hose clamps. If you go that route be gentle and don't make them too tight. As far as connecting the hose to the defrost vents on the passenger side vent the hose was able to just barely fit inside of the vent fitting. I think I had to make a slit in the hose to allow it to collapse a little. I attached it there with good quality duct tape. On the drivers side the hose just barely fit over the vent fitting and I attached that with duct tape as well.

I've had no problems with this setup and has held up fine after all these years.
 
I have new hoses to replace the make shift set up that's currently in there. Is there an easy way to do this get to the vents? Do the vents pop out from the top? Undo the dash? This is a pic of the passenger side defrost hose with the glove box removed. ( sorry for the upside down photo)
View attachment 1715144076
I just got done putting my hoses on my box and what I did was put the bushings in the hoses first and then used some RU-GLYDE to help slide them onto box. I then took some zip ties to help hold them in place!

DSC00068.JPG


DSC00069.JPG


DSC00070.JPG


DSC00071.JPG
 
Yup! That's the only way that kit works. Leave out one of the adapters but, then you lose air flow through the sloppy connection to the windshield vents.
Out of desperation one night I got on Nappa's website and after looking over the options for heater box hoses, I found the 2" and 2.5 " on their site. I ordered them in (6 ft lengths available only) and received enough to easily do two cars for less than the kit from DMT. Best part was I shared the cost with one of my friends and the hoses installed perfectly. Just had to use a little white grease on the hose ends to make it easier to install.

Can you share the part number and or supplier
 
Can you share the part number and or supplier

No problem 340_duster,

Here you go..

Nappa part number N0E8131509 ----- 2- 1/4" diameter

Nappa part number N0E8151001 ---- 2" diameter

Nappa part number NOE8155008 ---- 2-1/2 " diameter.

I've listed them all in case anyone else reading has a different diameter they need. I've used these on my 1968 Barracuda restoration and they work perfectly, plus, they look as close to factory as anything else I've seen.

Hope this helps!!
 
No problem 340_duster,

Here you go..

Nappa part number N0E8131509 ----- 2- 1/4" diameter

Nappa part number N0E8151001 ---- 2" diameter

Nappa part number NOE8155008 ---- 2-1/2 " diameter.

I've listed them all in case anyone else reading has a different diameter they need. I've used these on my 1968 Barracuda restoration and they work perfectly, plus, they look as close to factory as anything else I've seen.

Hope this helps!!
Thank You
 
Not to bash on the OP or anyone else in this thread but I've never understood why people have so much trouble with the defrost hoses.

First, you want a material that's flexible and not heavy. I can't tell for sure but the pics look like a heavy rubber type hose - not ideal.

Second, don't bother with adapters. There's not enough room for them and they cause more trouble than their worth.

Third, prepare to get creative with how to attach the hoses to the heater box as well as the defrost vents.

Here's what I did on my '71 Dart 13 years ago. Look online for some hoses with the correct ID to go over the heater box fittings without adapters. As other posts in this thread show they are different diameters. I found mine on ebay, generic hose ducting. Buy some length of that hose. Make sure the hose is flexible or can be formed from using a heat gun. I attached those hoses to my heater box with big zip ties, 1 on each, pulled tight with a pair of pliers. The factory clips for attaching the hose are nice if they're in good shape. You could also use duct tape (black color) if done correctly with a good brand of tape. Another option is going to the hardware store and looking and different types of radiator hose clamps. If you go that route be gentle and don't make them too tight. As far as connecting the hose to the defrost vents on the passenger side vent the hose was able to just barely fit inside of the vent fitting. I think I had to make a slit in the hose to allow it to collapse a little. I attached it there with good quality duct tape. On the drivers side the hose just barely fit over the vent fitting and I attached that with duct tape as well.

I've had no problems with this setup and has held up fine after all these years.

I use the same method. 2" lightweight flexible aluminum black hose ,(Dorman 96034, $13. bucks 2X), and black Gorilla duct tape. Seems to last forever if not disturbed.
 
so seem like the only way to get the the defrost vents on the dash is to take the dash apart? true?
 
it is the only way I know of, unless some else knows how to remove vents!
if I remember correctly you will also have to remove front windshield so that you can remove screws that hold the dash in, you can get to the two under dash!
 
I put mine in from under the dash. Ain't easy, radio out, seat out, gotta have room, whatever it takes. Aircraft scat tubing will work too. It comes in several sizes. I guess that I should say sceet tubing, it's black. Probably more expensive than NAPA.
 
I use the same method. 2" lightweight flexible aluminum black hose ,(Dorman 96034, $13. bucks 2X), and black Gorilla duct tape. Seems to last forever if not disturbed.
I know this thread is old, but...how brutal was the access? What did you have to take apart to get everything hooked up, and how long are the hoses when done? Since a shop had the cluster out to fix a few things, I lost my defroster airflow, and I'd rather not pay them a(nother) bunch of money to fix it.
 
-
Back
Top