The valve has been leaking fluids. I finally dropped down the cover and tackled the job.
First thing I found is that the pull wire dose not line up with the cable housing at the valve. This is why the valve is hard to move and seams like it is sticking. Yep its sticking because its pushing the pull wire off to the side and binding it. With a little persuasion from a pair of channel locks it is now straight and the valve opens and closes easily. Yahoo one problem solved without spending an $.Then I removed the valve and installed 2 new seals. 5 gallon of water in the tank, the valve opens and closes with 2 fingers, Its been 2 weeks and the discharge hose is still dry. All said and done the worst part of the job was the anticipation of it.

Do you have any photographs

Was thinking I had reported on this before, as the sheathing is too short and not in the clamp good, had to shorten the cable about 1/4 inch.
Think the problem you have will reappear.

Did not take any pic's, but on the 38GK, the pull in horizontal and the valve is line is pointed down toward the ground and tight fit trying to remove the bolts. 45 minutes to reassemble.

Sorry I didn't stop to take any pics, Maybe this help. Needless to say I didn't attend art school

Perfect sketch! Probably explains it better than any pic you could have got up there!