Abstract: A booster link arm positioning device for position or from a top to bottom position. The link arm is maintained by spring tension in the proper positions by the use of two torsion springs during first and second stage operations. In the second stage the link arm is disengaged from the hydraulic cylinder rollers and is maintained in a vertical position by a blocking bar. Upon lowering the upper frame to its bottom position, the link arm and yoke will re-engage with the hydraulic cylinder rollers at the proper location.