Defrost duct attachment question

Purchased the plastic defrost duct from Walcks which they tell me does not use a clamp to attach the actual flexible hose. It is supposed to just fit up inside the plastic. I bought some 2" diamater flex hose from the auto parts store which fits perfectly on the other end at the heater box. Matches the original hose which fell apart in my hands. I tried using tape to hold the hose in the plastic part but it just fell off after a short time.

Question: How do you attach a 2' diameter flex hose into the slightly larger plastic duct under the dash??? Does Walcks have a special hose that I should have purchased that somehow connects? Looking for a quick fix as it is no fun working up under the dash for very long....

Thank you,

Peter

 

had same problem went to my local hardware store got a white flexible hose I believe for a bathroom exhaust fan ( bought by the foot)and hose clamped it.still a royal pain installing good luck

 

Haven't gotten to my heater system yet but I'd....

Look for some kinda adapter at the hardware store to get the Defroster down to the size of your hose.
Think outside the box, look at plumbing reducers (PVC, CPVC, Conduit, Copper, etc), maybe shop Vac hoses,

For instance....This is a dust collection reducer from Harbor Freight:


check all types of PVC reducers (female/male) threaded and slip.

 

I slipped the 2" defrost duct into the vent tub and used three metal clips to hold it in.

Here is a picture of the clips.

 

You could also check out flexible hubless adaptors such as "Fernco" plumbing (waste) fittings. Come in all variations of reduction/enlargement.

 

I used a zip tie on the bottom outlet, and Gorilla Tape at the plastic duct below the windshield. The Gorilla Tape sealed tight, and has held up like new for over 3 years.




I've used Gorilla Tape for many different applications. It has always held tight and never failed. It's the best I have ever found. I buy it at Lowes.

 

I went to Lowes (or maybe Home Depot) and purchased a pvc adapter that necked down to 2 inches to accomodate the duct. I simply fastened them on with hose clamps.

The larger side of the adapter was just a little too large to fit in the plastic defrost unit, so I ground it down on a grinding wheel. It is a press-in fit into the plastic duct. If it falls out I'll use some duct tape to hold in or perhaps some caulk.

I also had to use a piece pf pvc on the plenum end and the pvc fit nicely into the plenum .

Now, the duct I used was a wagoneer duct that I purchased on ebay. I got three of them since I needed to do three jeeps.

Between that duct and the one under the hood jeep seems to be getting even for all those modifications that we do.....

 

I ended up using an exhaust tailpipe adapter for my hose adapter. There are many different sizes and shapes and they're low dollar. From a muffler shop or NAPA.

 

I used one of those black "wire lined" hoses that I slipped inside the defrost duct then I used a power drill to run 1 wood screw through the duct and into the hose then out the other side and I have had no problems easiest fix I could think of and likely the cheapest.

 

Great information as always from the group. Thank you. I like the Gorilla tape idea and have never used it. I did try regular duct tape and it did not hold. The clips are great as well. My short term fix was a wire connected to the 2" flex hose on each side and run up through the plastic duct. It is essentially hanging in the plastic duct opening but it should stay especially if I add Gorilla tape to seal and secure.
Now I need to figure out the controls to get the heat flowing into the defrost hose......

Thank you again.

Peter

 

You could use a hose clamp,,if you cant get one large enough you can hook them in tandem to each other.....
Now my question..I have a cj5 71 it has 2 hose outlets I know one goes to the defrosters..where does the other get plumed to???

 

I could be wrong but I don't think a hose clamp will solve his problem if the duct hose goes Inside the defrost duct.

 

nothing... i capped mine with the dust cover off of a can of hardener for urethane paint i suppose a spray can is about the same size

 

will this help

 

What service manual did that photo come from Twin 2?

Thanks for posting it.

 

twin 2 thats a great shot,, tks.
where did you copy it from?

 

Twin 2--great shot and thank you. That is exaclty my system. I have replaced the defrost duct and hose with new. The grill to heater hose up front and the 3 vacuum lines. I am now trying to figure out why I am not getting air out the defrost hose?? Is it something in the switch iteslf which seems to redirect the vacuum lines? I am also wondering if the circular pieces where the vacuum lines go to...are those some type of diaphram?? If so maybe the one at the end of the Defrost switch has failed and needs replacing?? I do not see how to replace those or even get them out at this point.
The heater does work and blows well currently. Always has. Just nothing up the deforst hose. I do think it is a switch/vacuum line issue that I cant locate at this point.
Peter

 

peter . the best way to check the diaphrams , is us a hand held type vacuum pump . that will tell you if it is bad or not . the diagram I sent was out of the FSM . that I picked up 30 something years ago . when I first got the jeep .vacuum hoses need to be hooked up as diagram shows .as to the vacuum switch itself there are no moving parts inside of it . only the back of switch rotates when you push buttons . are all the springs there . heres a picture of one I was working on the other question is the FSM . I'll just add picture here
inside cover