Another thing to keep in mind is that often the binding or hard to move gate valve may not actually at the tank. More often than not, with the water panel design of many GDRVs (and other manufacturers) where the black tank flush is above the black/grey tank pull handles, after flushing and disconnecting the hose, water streams back out of the black tank connection. And you guessed it or already have observed that it runs down splashing all over the pull handles. Over time rusting sits in and thus the pulling harder and harder until the handle will not move or may even break.
I place heavy towels over my pull handles to absorb the water and keep the pull handle area of the panel dry. I do lube the cables at the panel with silicone spray lube while moving the handles from open to closed a few times. I have even lubed them behind the panel a couple times as well. Going into out 8th season all three work like they did in 2014.
There is also a device which clamps onto the cable with an opening to spray lubrication into a small hole which help to lubricate the cable as well. A few folks have shared pictures of this device with positive feedback. Searching the net will find a picture as well.
Dan
