(37) Wash all of the blower parts In dry cleaning solvent (item 10, Appendix B).
Death or serious injury could occur if compressed air is directed against the skin. Do not use compressed
air for cleaning or drying unless the pressure is/has been reduced to 30 psi (2 11 kg/cm2) or less. When
working with compressed air always use chip guards, eye protection and other personal protective
(38) Dry all of the blower parts using compressed air.
(39) Examine the bearings for any indications of corrosion or pitting. Lubricate each ball bearing with light engine
oil (Item 17, Appendix B). Then, while holding the bearing inner race from turning, revolve the outer race
slowly by hand and check for rough spots. The double-row ball bearings are pre-loaded and have no end
play. A new bearing will seem to have considerable resistance to motion when revolved by hand.
(40) Check the oil seal rings, carriers, and collars for wear or scoring. If worn excessively, they must be replaced.
The current oil seal rings are chrome flashed and the carriers are liquid nitrided. When replacement of an oil
seal ring or carrier is necessary, both parts must be replaced together.
(41) Inspect the blower rotor lobes, especially the sealing ribs, for burrs or scoring. Rotors must be smooth for
satisfactory operation of the blower. If the rotors are slightly scored or burred, they may be cleaned up with
emery cloth (item 13, Appendix B).
(42) Examine the rotor shaft serrations for wear, burrs, or peening. Also inspect the bearing and oil seal contact
surfaces of the shafts for wear or scoring.
(43) Inspect the inside surface of the blower housing for burrs or scoring. The inside surface must be smooth for
efficient operation of the blower. If the inside surface of the housing is slightly scored or burred, it may be
cleaned up with emery cloth (item 13, Appendix B).
(44) Check the finished ends of the blower housing for flatness or burrs. The end plates must set flat against the
(45) The finished inside face of each end plate must be smooth and flat. If the finished face is slightly scored or
burred, it may be cleaned up with emery cloth (item 13, Appendix B).
Be careful not to remove metal at the joint face between the end plates and the housing. Air or oil leaks
could develop after assembly.
(46) Examine the serrations in the blower timing gears for wear or peening. Also, check the gear teeth for wear,
chipping, or other damage. If the gears are worn to the point where the backlash between the gears exceeds
Q.004 in. (0.102 mm) or damaged sufficiently to require replacement, both gears must be replaced as a set.
(47) Check the blower drive shaft serrations for wear or peening. Replace the shaft if it is bent, cracked, or has
excessive spline wear.