Grey Tank valve 1 sticking

[lcompton]

New to site, and I hope I`m posting this in the correct forum. I have a 2013 Jayco Pinnacle 36' RSQS 5th wheel. Grey tank 1 valve is not moving all the way out. Cable will pull out about 1". I have pulled my panels in cargo hold to check the valve, and it will only retract about an inch. other valves retract all the way and fully operational. This one seems to be hung or caught on something, as it will not move any further. Has anybody experienced this problem, and how did you correct it?

[abarkl]

We regularly apply a coating of white grease to the valve to handle rod.

Welcome to JOF.

[lcompton]

Thank you for responding. I`ve checked the movement of the cable and I have free movement of it. The problem seems to be in the valve or gate it self inside the housing. When I pull the handle it move about an inch and it seems as if the gate is not sliding into the channel as it should. I believe I will have to replace the valve, but my current problem is how to drain the tank so I can replace it. So I guess I'm looking for some way to drain grey tank 1 if that valve is not operational. Thank you for any help or advice.