There are several reasons the dump truck cylinder may be missing stages of the extension or retraction operation the sleeve’s Pack/Seal or Bearing is not moving or may be too tight, prohibiting the sleeve from extending or retracting in the proper sequence, the Cylinder that the body or unit is mounted in may have a worn or damaged part. This causes the cylinder to sideload, not allowing the sleeve to extend or retract in the correct order, and a bent, egg-shaped, or bulging sleeve can cause tightness, resulting in the sleeve being unable to extend or retract appropriately.