Most often the handles screw into the slide valve. I'm not sure what you mean when you say you "pulled the panel and the rod handle was connected"...hold onto the handle and try to screw it back into the slide valve. Unless it's broken, you should be able to do so. If that doesn't work...well, it's gonna get messy so pick a suitable spot to 'fix it'....(if you've got a teenager, make sure they're around for a YouTube spot)
First thing I'd do is inspect it with the stinky slinky removed. Reach into the opening and pull the handle very slowly. If you can't reach it yourself have someone (whom you trust) do it for you. You will be able to feel the knife valve move when the handle is gradually pulled. If it doesn't move, then the handle has either come off or broken off. Either way, if the valve does not move, then you'll have to 'pull the valve open' another way. My first choice would be to open up the area where the handle goes into the valve using a large drill bit. You might be able to reach in with some needle nose pliers and grasp the broken area and pull it open. As a last resort, you'll have to open it from inside the business end of the tube using a screwdriver which will be very messy....good luck....Dennis
To replace the entire knife valve completely:
There are four screws that hold the knife valve in place on the dump mechanism. Remove those four screws and the entire valve will come out for replacement. Make sure BOTH rubber O rings are in their grooves before reinstalling the screws or it'll leak.....D
