The Stovebolt Site Forums The Shop Area Interiors Defroster deflector -53 half ton

Just my theory about the rubber sleeve on one side, although yours sounds reversed from my truck ...

The hose inlet on the drivers side defroster deflector at the windshield on my '54 3100 is larger than the diameter of the deflector on the passenger side. The two outlets for the hoses on the heater body are the same diameter. If a larger hose is used on the drivers side, then a rubber sleeve must be put over one of the outlets at the heater to increase its diametet to match the larger heater hose on that side. A larger hose may have been used on the drives side because it is longer than the hose on the pasenger side and would therefore have more total resistance to the air movement.

Or maybe someone just screwed up and put the wrong size deflector on the drivers side of my truck??

The sleeves are shown in the Accessories Installation Manuals for various years. Although I believe that their number and locations may be different for different years.

By the way, I have a rubber sleeve for one of the outlets supplying air to the drivers deflector, but haven't put it on yet or installed a larger hose on that side. So for now, both hoses are the same diameter. I jammed the defroster hose inside the large inlet on the drivers side, and fitted it over the small inlet on the passenger side. The hoses fit on the heater outlets without sleeves.