4-20. Removal of Spraying Pressure Air Regulator.

TM 5-4940-228-14 around head to tank seal. Replace gasket if air is heard, replace regulator if no air is heard escaping (Fig. 4-2). 4-20. Removal of Spraying Pressure Air Regulator. Loosen nut on union (30). Use a small pipe wrench and loosen nipple (45) on tank head (50); this will allow you to swing all associated plumbing away from tank head (50). Remove nipple (41) from spraying pressure air regulator (42), parts items 41, 40, 39,29, 7, 28, 27, 26, and 7 will all be removed as a sub-assembly. Remove spraying pressure air regu- lator (42) from nipple (43). 4-21. Installation of Spraying Pressure Air Reg- ulator (42). NOTE Use of a hydraulic sealant or teflon pipe thread tape would be helpful to prevent leaks. Screw spraying pressure air regulator (42) onto nipple (43). Screw sub-assembly items, 41, 40, 39, 29, 38, 7, 28, 26 and 7 into spraying pressure air reg- ulator (42). Tighten nipple (45) which will rotate associated plumbing toward union (30). Align union (30) and tighten. Attach pressure tube (5) to fitting (7). 4-22. Removal of Fluid Pressure Air Regulator. Remove adjusting screw from regulator (33), un- screw fluid pressure air regulator (33) from nipple (34). Unscrew street elbow (32), with nipple (31) and half of union (30) and remove fluid pressure air regulator (33). 4-23. Installation of Fluid Pressure Air Regulator. Remove adjusting screw from regulator (33), screw fluid pressure air regulator (33) onto nipple (34). Screw street elbow (32) (with nipple 31 and half of union) into fluid pressure air regulator (33). Tighten nipple (45) until proper alignment of union (30) is made and tighten union (30) nut. 4-24. Removal of Slide Valve (35). Remove fluid pressure air regulator (33) as de- scribed in para 4-22. Remove nipple (34). Remove slide valve (35) from tee (36). 4-25. Installation of Slide Valve (35). Screw slide valve (35) into tee (36). Install nipple (34) into slide valve (35). Follow installation in- structions for installation of fluid pressure air regu- lator (para 4-23). 4-26. Removal of Air Motor. a. Remove pressure hose assembly (5) from nee- dle valve (14). b. Loosen setscrew in coupling (6) which holds coupling to air motor. c. Loosen two setscrews on top of housing (16), lift air motor from housing. 4-27. Installation of Air Motor. a. Put air motor (15) into top of housing (16), place by tightening two setscrews on top of housing (16). b. Install nipple (13) and muffler (8) into air motor (15) body. Install needle valve (14) and adapter (7). Screw end of pressure hose (5) onto adapter (7). c. Slide coupling (6) over motor (15) shaft and tighten setscrew in coupling (6). 4-28. Adjustment of Packing (19). a. Loosen two setscrews at top of housing (16) to allow housing (16) to rotate without rotating air motor also. b. Unscrew locknut (17) which holds housing (16) in position. c. Slowly screw housing (16) into tank head (50), this will compress packing (19) around shaft (20) by hand. When shaft becomes difficult to turn, un- screw housing (16) 1/8 turn and tighten locknut (17). d. Tighten two setscrews at top of housing (16) to hold air motor (15) in place. e. Go through operational checkout of paragraph 4-19. 4 - 8