HF-7-600 Page 20
21. Remove the 6 socket head screws (21) and washers (20) that attach the bearing housing (24) to the air
Cylinder (22).
22. Remove the bearing housing from the air cylinder using two 2 jaw pullers. The puller jaws must be narrow
enough to fit in the rectangular holes in the bearing bosses. A shaft protector (soft spacer) must be placed
over the end of each rotor shaft. Both pullers must be tightened evenly during this process. There are 2
dowel pins that locate the bearing housing relative to the air cylinder. If the bearing housing is tilted during
removal these dowel pins may break out of their holes.
23. Remove the 2 seal flingers (34) from their bores in the bearing housing.
24. Remove the ball (14) and roller bearing (35) from their bores in the bearing housing using a ball peen hammer
and punch. Exercise care not to damage the bearing bores.
25. Position the blower assembly horizontally.
26. Match mark the rotors by making small punch marks on the ends of meshing lobes.
27. Push the drive rotor (23A) shaft through the air cylinder using a 2 jaw puller. The puller jaws must be narrow
enough to fit in the rectangular holes in the bearing boss. A shaft protector (soft spacer) must be placed over
the end of the rotor shaft. Remove the drive rotor from the air cylinder.
28. Push the idler rotor (23B) shaft through the air cylinder using a 2 jaw puller. Remove the idler rotor from the
air cylinder.
29. Remove the 2 seal flingers (34) from their bores in the air cylinder.
30. Remove the 2 ball bearings (14) from their bores in the air cylinder using a ball peen hammer and punch.
Exercise care not to damage the bearing bores.
31. Inspect the 3 piston rings (15) on both ends of both rotors for signs of damage and abnormal wear. Remove
the piston rings from each of the 4 ring carriers (33).
32. Inspect the ring carriers for signs of damage and abnormal wear. Normally it is not required to replace the
ring carriers.
33. If a ring carrier is damaged it may be removed by heating with a torch. The rotor should be placed in a
vertical position and continuously rotated while the ring carrier is being heated. Caution should be used when
performing this procedure as the rotor can be damaged by uneven and extreme heating.
34. Inspect the inserts (32) in the 4 bearing bosses (2 in bearing housing and 2 in air cylinder) for signs of
damage and abnormal wear. Normally it is not required to replace the inserts.
35. If an insert is damaged it may be removed by using a hydraulic press and suitable driver tool. It must be
removed from the air side of the bearing housing or air cylinder.
