I am hopeful someone can help with my dilemma.I cannot in my manual find any information on the knob in the center front of my seat.I assume it is to adjust air tension in the seat.Since washing my tractor last night when I get on the seat and get off there is a whoopee cushion effect though mercifully less noise.I assume it has got a wee bit of moisture around the air intake and exit.Is this the principle of the seat? For the knob adjustment to increase or decrease air in or out when the rider sits on it?My tractor is very new so I'm still in the "paranoid" stage LOL but she sure works nice. Eldon C.