Well I went out to the shop today and thought "What have I got to lose??" I dissembled the valve, cleaned and burnished the shaft. I expected to see a torn O-ring but they looked OK...Maybe a little worn. I lubed it with petroleum jelly and reassembled. It is working great now. However this experience prompted me to research for replacement. After studying Norgrens tech sheets on their web-site I found one on ebay which is a slight different model # but might work for $65. You can tell that an engineer determined the model numbers....It appears the different digits denote a particular component that makes up the whole unit. At that point I saw Richards suggested options, my inner frugal self took over and I ordered the $17 Amazon one!!! I will review and report my findings. Thank you , Richard !
1993 Newell (316) 45' 8V92,towing an Imperial open trailer or RnR custom built enclosed trailer. FMCA#232958 '67 Airstream Overlander 27' '67GTO,'76TransAm,'52Chevy panel, 2000 Corvette "Lingenfelter"modified, '23 Grand Cherokee.