Plastic water drain valve
In the course of draining my water system, I have somehow gotten a stuck (open) grey plastic/nylon? drain valve under my galley sink on my '89 Excella. The valve is a screw type with a small 't' handle. All of the other ones (there are three others) on the trailer opened and closed as they were supposed to.
Are these little buggers re-buildable? If so, how does one disassemble? I have tried relentlessly to get this valve to re-close, pushing down while turning but the handle just turns and the valve does not move. Anybody have similar experience and/or successful repair?