Removal and replacement of the devise is fairly straight forward. You don't have to remove the hydraulics or related parts. Only remove the pressure differential valve. Actually replacing the diaphragm not difficult as long as you follow the included service info.
I at first thought this was a sealed unit. It's not. There are two calibrated bleed holes, one in each side of each shell. (pictured)
I found the inside of the shells and the attached shaft to be dirty and sticky. (pictured) Cleaning these up made a difference in operation.
