TM 55-1730-201-12 28.  HYDRAULIC  CYLINDER  STICKS  AT  FULLY EXTENDED  POSITION. PROBABLE   CAUSE POSSIBLE  REMEDY Piston   extended   too Remove   safety-lock,   open far  and  riding  on by-pass   valve,   and   jar inner   cylinder   wall upper  structure  down until   piston   is   re- leased. 29. PLATFORM WILL NOT LOWER OR LOWERS SLOWLY. PROBABLE   CAUSE POSSIBLE  REMEDY Piston   packing   ruptured Replace   piston   packing (paragraph   37) PROBABLE   CAUSE By-pass   valve   sticking (will   not   fully   close) High   pressure   hose leaking 30. HAND PUMP FAILS TO OPERATE PROBABLE   CAUSE Pump  piston  or  cylinder scored   or   scratched Ballsprings   weak   or broken Section  IV.  HYDRAULIC  SYSTEM 31.  GENERAL. (1)    Disconnect The   hydraulic   system   which   functions   to   supply from  the  tee  (2). fluid   under   pressure   to   the   cylinder   assembly   con- (2)    Disconnect POSSIBLE  REMEDY Clean   valve   of   obstruct- ing   foreign   material (paragraph  33) Replace   high   pressure hose  (paragraph  36). POSSIBLE  REMEDY Replace   a   defective piston   or   cylinder (paragraph   37) Replace   a   defective ballspring  (paragraph 37) the   hose   assembly   (5,   figure   5) the   suction   tube   assembly   (4) sists   of   a   hand-operated   hydraulic   pump,   a   by-pass from  the  reducer  (3). valve,   lines   and   fittings, hydraulic  cylinder,  and  a fluid    reservoir. (3)   Disconnect   the   by-pass   tube   assembly   (1) 32. HYDRAULIC HAND PUMP. a.   Removal from  the  tee  (2). (4)   Remove   the   two   bolts   (37),   lockwashers (32),  and  nuts  (31)  that  secure  the  pump  body  (36) to  the  bracket  and  remove  the  pump. Legend for Figure 5: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. Bypass  tube  assembly Tee- Reducer   tube Suction   tube   assembly Hose  assembly Elbow Return   tube   assembly Return   tube   adapter Tee Nipple Hydraulic   strainer   plug Screen. Gasket Strainer  body 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. Valve   assembly Washer Nut Elbow Pin Connecting    link Handle   socket Bolt Handle   assembly Spring Cotter   pin Nut Setscrew Nut 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. Elbow,   90° 32. Washer 49. Elbow,   90° 33.  Preformed  packing 50. Screw 34.   Nut 51. 52. Gasket Pump body Bolt Pivot   pin Nut Bearing O-ring Preformed   packing Valve   seat Preformed   packing Ball   bearing Spring Piston Plug Preformed   packing Ball   bearing Spring Preformed   packing 9