I recently replaced the heater boxes on the Wonderbus in an effort to get rid of the exhaust fumes coming into the passenger cabin with the warm air. I was disappointed to see that the inside of the old heater boxes, inside the hot air on-off flap, were gray and clean-looking. Didn't look like any exhaust was leaking there. At first the new boxes seemed perfect -- there was an initial smell of paint, but that faded away. I do have hot (warm) air. But now the exhaust smell is back, especially noticeable while idling at a light.
Olli Lammi mentioned that he also had exhaust fumes (see thread "Screw Size?") but traced it to a leak and an unconnected crankcase breather tube. When we were replacing the heater boxes we inspected carefully and found no obvious exhaust leaks. But my inspection of the missing cooling tin parts revealed that my crankcase breather tube thing is not connected. This might be part of the problem?
Where might a fellow connect his breather tube if he has dual Kads?