Thanks for your response and info. They are cable pushed and pulled. They are very hard to work, so I figured they wasn’t closing all the way because I had to put a valve on the outlet for the sewer hose to attach. There possibly could be something in them. I have tried the tank blaster wand for the back tank with no results. The front tank is impossible because of the way the sewer is routed to the tank. I will try the drain valve lubricant and see what it does. Hope that will do it, it will be a pain in the butt to find and fix them I’d think. I called Keystone for a diagram but they want a dealer to fix it. I don’t wanna pay their price, since I am capable of the repair. Lol
