Flapper Box Control
 

While I was under my car I noticed both flapper box cables had come loose so I reattached them. What controls their opening & closing? The heater lever next to the parking brake opens & closes the dampers on the hot air pipes from the heat exchanger but what opens & closes the flapper boxes??

Thanks,
Ron

Hi Ron

On my 66 I have two sets of cables which attach to the bottom of the heater control lever by the e-brake. These cables - 2 complete cables which are one piece folded in half - which makes four at the back end of the car! how confussing! go to both the flapper boxes and the dampers on the hot air pipes from the heat exchanger.

So it all works at once from one pull of the lever

Hope that makes sence

David

David:
Thanks for the information. it makes perfect sense.

Ron

If you order new cables, they are slightly different lengths. I recommend you order two of the longer ones (the one that costs slightly more). I replaced mine with one of each, and the short cable barely reached.

Rick

My controls as is work well and I get heat. So what is a "flapper" ... I have only one cable from each lever?

Jac912:
Maybe your heat exchanger damper boxes were removed by the PO. As I recall the european version 912 did not have them.

I think my 69 has three dampers per heater box, I'll have to check.

Ron

jac912,
On U.S. heaters the flappers are part of the metal box below the cylinders. They're spring loaded open by default and let the heat pushed by the fan out the bottom of the car. When you pull the lever inside the car, the flaps start to close and redirect heated air into the ducts leading inside the car.

The other cable goes to the rotating air valves forward of the engine, also spring loaded.

O.K. I see the rotating air valves. They are not hooked up. What do they actually do?

I just checked the manual, where the valves are called air gates. If the cable breaks (or is missing), the air gates are designed to block air from traveling inside the car, and instead release the heated air back outside thru the four openings you see under the car. So unless the gates are stuck open (letting air inside) right now, if you install a new cable you should be getting a lot more warm air inside this winter.

Rick:
You are right. The Flapper Gates were wide open even though the cables were disconnected from the levers. All the gates default to the open position dumping hot air to the outside.

Thanks,
Ron D