I thought that I would post the 'failure' sequence of our leak in the treadle (accelerator pedal) so that others might benefit from the 'alert to imposing problems'. I have not yet fixed the problem but that is imminent.
(1) while driving down the highway (two day's journey from the coast) a couple of months ago (parked mostly since then), I noticed the oddity of the white needle on the air pressure gauge (rear tank, but also plumbed for other auxiliary uses) dropping in spite of me not touching the brakes. The recovery was quite quick, back up to match the pressure of the red/orange needle. So... a leak was occurring somewhere, but seemed to resolve itself quickly.
(2) after a short drive today (exercise !!) and a stop to fill up on water ( we are in the same campground as 'hosts' through the summer) I lost all pressure in rear tank (white needle in the gauge) within 25 minutes.
(3) after parking, a steady hissing could be heard somewhere in the front end. Investigation with soapy spray showed little but following the sound led to the valve that is the lower part of the treadle. Interesting enough that having the engine running (and thus having a steady supply of air) I found the steady stream of air from the 'exhaust port' of the valve. Plugging the hole with my finger while lying under the front end resulted in an immediate revving of the engine. Pretty neat trick when outside the vehicle lying on the ground! Thus, the problem was confirmed, and a solution is suggested = a happy owner who now knows the solution to a vexing problem!
Woody,
You probably already saw my thread on rebuilding the throttle valve, but if not:
Williams Controls WM453109 Air Throttle Valve (http://www.foreforums.com/index.php?topic=27762)
Thanks, Chuck, I did see that. I just removed the unit and am now looking for a repair kit locally. The part's number will be very helpful.
Thanks