Well, I got them off. It was just oxidation holding them on, but working space was limited and the valves moved up or down every time I tried to romp on the caps. Caps hold the joystick to the valves with a pin and a bolt. Finally decided to put the bolts back in, held the bolts with a pair of pliers and then tapped the pliers til they came off. Replacing the O rings is @ 1/2 to 3/4 hour job if you know what to do.