4-18. PUMP, PIPING, AND VALVES - Continued
(6) Pry the link mount (4) and key (5) from the rotation tube (3).
(7) Remove four screws (6) and lockwashers (7) and slide pattern control bracket off elevation shaft (23).
Pull the elevation shaft (23) out through the bottom of the base (9). Use extreme care so as not to
damage the bushing in the top of the rotation tube (3).
(8) Remove screw (24) that retains the rotation tube (3) to the body (25).
(9) Pull the rotation tube assembly (3) out through the top of the body (25).
(10) Remove O-rings (34 and 35) from rotation tube assembly (3).
(11) Separate the body (25) from the base (9).
(12) Remove rotation bearing (27) and O-rings (28, 29) from the base (9).
(13) Remove capscrews (30) and washers (31) that retain the base (9) to the plate (32).
(14) Remove the base gasket (33).
(15) Remove the ball bearing (26) from the base (9).
(16) Remove the bearing seal (36) and O-ring (37) from the base (9).
Small lime deposits can be dissolved by soaking components in acetic acid (item 1, Appendix E)
and then rub them with a brass bristle brush.
(17) Remove lime deposits, scale, or corrosion from the base, body head, rotation tube, and shaft using a
brass bristle brush.
(18) Inspect base (9), body (25), and head for corrosion, cracks or any other damage that may cause water
(19) Inspect bearings following procedures in para. 4-9.
(20) Inspect elevation shaft, segment gear, rotation tube and mounting link for damage.
(21) Evidence of damage of any kind is cause for rejection. Replace component or assembly as required.
To reduce the possibility of O-ring damage, apply silicone grease (item 27, Appendix E) to all O-
rings and their sealing surfaces prior to installation.
(22) Install base gasket (33) onto turret base (9).
(23) Install base plate (32) and align mounting holes.