Should I be maintaining this valve in any way? It's 2.5 years old and really feels like it's binding when I go from setting to setting. Think some O ring lube or something inside would go a long way. But I don't want to open it up and find you can't, or shouldn't. Or worse, have parts go flying all over the place when I pull the cover. I figure I need to do this, if I am, before I open the pool and it fills with water. Any advice is appreciated.