TM 5-4940-228-14 Key to Figure 4-2: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. Control head assembly Fluid post Propeller screw Propeller Pressure hose assembly Coupling Fitting  (3) Muffler Cup Screen (2) Felt (2) Base Nipple Needle valve Air motor Housing Nut Packing  washer Packing Propeller shaft Adapter Fluid strainer Shut off cock Shut off cock Pressure gage (2) Air  filter Nipple Tee NOTE If air supply is not available to you, connect  pressure  tank  to  compressor assembly.   Follow   operation   pro- cedures of Chapter 2 but, do not con- nect spray guns or use any paint. (6) Listen carefully for any air leakage. Obvi- ous  air  leaks  must  be  repaired  before  proceeding (Fig.  4-2). WARNING Before  attempting  any  repairs,  re- move all air pressure from the tank. An attempt to remove parts while the tank is pressurized could cause those parts to be blown free and inflict in- jury. (7) Look  at  both  pressure  gages.  Both  gages should indicate zero pressure. If not, the air regu- lator next to that pressure gage is damaged and re- quires replacement (Fig. 4-2). Pressure gage can be removed directly from pressure tank if defective. (8) Slowly open needle valve (14) ; watch cou- 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. Nipple Union Nipple Street elbow Regulator Nipple Slide valve Tee Nipple Nipple Tee Nipple Street elbow Regulator Nipple Cross Nipple Elbow Nipple Safety valve Gasket Tank head Insert pail Tank Clamp (6) Pin (6) Clamp screw (6) pling  (6)  thru  slots  in  housing  (16).  If  coupling  (6) does  not  rotate,  or  if  motor  suddenly  rotates  rapidly, air  motor  is  damaged  and  requires  replacement (para  4-26). (9) Observe  pressure  gage  next  to  spraying pressure   air   regulator   (42)   while   tightening spraying   pressure   air   regulator   (42)   adjusting screw  slowly  until  a  20  psi  reading  is  reached. Watch pressure gage for two or three minutes. Pres- sure should not change more than 2 psi, if it does, spraying pressure air regulator (42) is defective and must be replaced (para 4-20). (10) Move  slide  valve  towards  fluid  pressure gage.  Observe  fluid  regulator  handle,  adjust  until 10 psi is reached. Open slide valve (push toward reg- ulator);  air  should  be  released  from  the  tank  and pressure gage should read zero. Failure to reach 10 psi  or  return  to  zero,  indicates  a  defective  slide valve which requires replacement (Fig. 4-2). (11) Move  slide  valve  towards  fluid  pressure gage. Observe fluid pressure gage while tightening fluid regulator handle to 40 psi. Watch gage for two to three minutes, pressure should remain constant. If  40  psi  could  not  be  reached,  listen  for  air  leak 4 -7