The holding tank valves were balky -- this probably is why the T handle on the black tank rod broke. I had been spraying the rods and the insides of the valves with silicone spray every so often, but the spray had little or no effect. (Everyone says not to use WD-40 because it might damage the seals, so I didn't.)
I did some research on this forum and elsewhere and found that some folks had retrofitted zerk fittings onto the valve body to enable them to inject grease under pressure. This might work, but it seemed kind of extreme. So I decided to try a much simpler fix.
After the tanks were completely empty (crucial step!), I pulled the valve rods all the way out. I then dabbed a little white lithium grease onto the rod and worked it back and forth.
It made a huge difference, and was so easy. We will see if this effect lasts very long. But even if I have to apply lithium before every trip, it will be worth it.
In theory, I could re-apply lithium to the rod every time we dump the tanks. In the real world, I am usually pretty preoccupied while dumping and am unlikely to engage in preventative maintenance at that time.
2012 Fun Finder X-139 "Boondock Style" (axle-flipped and extra insulation)
2013 Toyota Tacoma Off-Road (semi-beefy tires and components)
Our trips -- pix and textAbout our trailer"A journey of a thousand miles begins with a single list."