I carry a can of silicone spray in my wet bay.  Every once in a while, after I've openned the valve, a spray a little silicone on the metal shaft, then open and close the valve a couple of times.  You'll be amazed at how easy the valve will open after that.

Best Regards!

Hi Paul:

Thanks for the tip. I tried it and it really works.

You're very welcome!

Best Regards!

An interesting post I saw the other day, a guy had drilled and tapped a hole for a zirk fitting in the case of the handle and pumped it up with grease. Said it worked real well. Haven't had a chance to check it out but was also a good idea but certainly not as easy as spraying with silicone. I'm gonna try the silicone first! I occasionally used WD40 but it attracts dirt.

That silicone spray is great stuff.  I've used it on the jacks, tv antenna, and locks.  Never even thought of using it on the dump valves - thanks for the hint.