>> Trying to put in a shutoff valve for the heater, since the one under the front doesn't close properly. ~(;)> <<

   Even assuming a good fix, try laying an unabridged dictionary in
the pass through and drive, say, 200 miles at highway speed until
stopping. (don't forget cooling off idle)

  Lift the book up, feel underneath there and report back to me.

Geo/ATL