(5) Reset the top preformed packing (there are two preformed packings) on belt tension gage (4) so that it butts up
against the bottom of the handle.
(6) Set the lower preformed packing on the (deflection) scale to 5/16 inch (0.79 cm).
(7) Place gage (4) in the center of belt (5) and press on the gage until the belt is deflected downward 5/16 inch. This
can be judged by noting when the lower preformed packing on the gage lines up with the lower edge of the
(8) Remove the gage and read the top (force) scale just beneath the upper preformed packing. The number
beneath the upper preformed packing is the force in pounds which was required to deflect the belt 5/16 inch. The force
should be between 3.7 and 5.4 ft-lbs.
(9) If drive belt tension is not between 3.7 and 5.4 ft-lbs. loosen four nuts (6) to allow the air compressor drive
motor (8) to be moved.
(10) Turn jackscrew (7) clockwise (to the right) to tighten the drive belt. Turn counterclockwise (left) to loosen the
Figure 4-91. Air Compressor Drive Belt Adjustment