Cleaning ductwork

[6T5VAIR]

Hello all.

My late father's 32 year project is on the road now, but smells like a mouse's home. When I ran the cabin heater fan nesting material dumped out of the ducts onto the cabin floor. Mice had been in the cabin at least a little bit when I first pulled the car from it's backyard shop.

I am thinking to pull the seats, the carpet and then attack the ductwork. But I really don't know what I'm getting in to at all, this is all new to me. I have most of the available literature on the car on hand by the way.

So, looking for advice as to how to proceed:

Am I better off to just use vacuums and blowers and then an aerosol disinfectant on the ductwork perhaps? Sounds like the forward ducts are a challenge to remove. Note I also need to pull the speedometer which just broke, the stereo only works on one of four speakers, the power antenna isn't working, and the heat temp gauge is pegged to hot, so I might be pulling the dash anyway?

For the carpets I thought to just pull the entire set out after removing seats and then washing it outside the car.

Any advice from those with experience and wisdom would be much appreciated....

[Lane66Monza]

Model and year of car is crucial. Different tips for different Corvair's heating systems

[Dennis66]

From his title and searching a previous post, he (they) have a 1965. The long plastic duct could be a problem. I recently had a full dresser cycle that had been sitting for some time, long enough for rats to get involved. I tried every kind of cleaner and soaking and the rat pee smell just wouldn't go away (in the plastic air cleaner box). Eventually it got weaker with time. If it comes down to it, a replacement duct might be the answer. Dennis

[6T5VAIR]

It's a 65 Monza.

Replacing ductwork sounds expensive, but I can't think why my situation would end up being better than yours was...

[Frank DuVal]

Remove plastic duct, vacuum out as best you can. Vacuum a string through it, then use the string to pull bleach rag/wipes through it.

Then do same for plastic ducts in the front of the car.

And of course the upper engine shroud (aka turkey roaster) and lower shrouds need to be vacuumed.

[rcavictor]

Vacuum a string through it,

Great hack, love this.
Wealth of experience :)

[manvair]

I recently did this in my 65 monza. The duct was packed solid with nests over most of its length. Vacuum did nothing. I ended up removing the duct, and using a long piece of heavy wire with a hook bent on the end to fish out the contents. I also had to do the same for the Y duct under the dash, and the heater box, both of which also required some repairs.

[Lane66Monza]

I did a major rework of my 66 More Door which included touching items related to the heater system. Lower shrouds and front panels with duct adapters were bead blasted and painted. The 90 degree steel elbow on the end of the long heat duct was bead blasted and painted. New hoses were installed. The long heat duct, transition duct and defroster duct were removed. Signs of mice habitation was present in the long heat duct. All plastic ducts were cleaned with soap and warm water. Then a rag soaked in Lysol disinfectant was dragged through the long heat duct. If it came out with residue, another one was put through. This was repeated until we got a clean rag to come out. Yes, nylon string was tied to each end of the rag to get the job done. Some minor repairs were done to the plastic after the cleaning. The transtion duct and defroster duct were submersed in warm water with Lysol. They were washed with a rag and brushed inside best we could.

We only had a new paint smell and oil smell when we used the heater system. Both attributed to the engine work and engine sheet metal painting that was done.

[Dennis66]

By all means try cleaning before replacement (note I said "might". I had used bleach, vinegar, purple power, but there are other cleaners that I hadn't tried. Obviously, it will require removing the long duct. When I was a kid, we used to take them out and throw them away as most of my Corvairs lacked the hoses and the duct and blend box were "in the way and extra weight". Less cold days down here in Florida, and I was young and dumb then. Dennis

[6T5VAIR]

What's the procedure to remove the long duct?

[RexJohnson]

Remove the tunnel covers from under the car. There should be a brace under the rear seat area and then a strap at the very back. You also have the large oval hose at the rear. If it is the original hose, still good and you want to save it. They never really want to come off of the duct without destroying the hose. In that case I remove the hose with the metal elbow attached to the heater box. There are 3 screws that are easy to get to. Once the hose is loose just wiggle the duct side to side as it sits on top of the tunnel side and pull back and it will come loose them the front.

[66vairguy]

I've removed all the heater parts on two LM cars. One thing I learned the front end of the long duct that the front heater/defroster tube fits in is sometimes broken. Not sure why, maybe rough handling by folks, but it's been reported as a problem on forums. Of the two I did, one duct was broken and had to be replaced. The long plastic duct is durable if you are patient removing it, don't forget to remove ALL the screws. Towards the rear there is a metal bracket riveted to the duct and folks seem to miss taking out the screw and break the bracket off the duct.

I formed a few wire coat hangers together with a rag on one end. I poured a half gallon of "Simple Green" in and drag the rag through the duct, the repeat from other side, flushing out the duct between each pass. One duct was packed with oily grime, the other was just full of dirt. Both cleaned up nicely and after I assembled the heating system it smelled great.

[Jim65]

I had some nest in the heater duct, but they also like to live under the shroud on top of the finned cylinders.
The nastiest part was the enclosure for the heater fan. They used it for their bathroom. It was full of mouse droppings.