TM  55-1730-201-12 and  security  of  the  plate  to  the  platform. (5)   Replace   any   defective   parts. c.  Installation. (1)   Position   the   platform   handrails   (1)   on   the platform   assembly   (23). (2)   Position   the   platform   on   the   four   stair   sup- ports   (22)  and   secure   with   four   pivot   pins   (3)   and eight   cotter   pins. (3)   Secure   the   hydraulic   cylinder   assembly   (21) to   the   platform   with   two   pivot   pins   and   four   cotter pins. 41.  HANDRAIL  ASSEMBLY. a.   Removal. (1)  Remove  the  two  bolts  (2,  figure  1)  and  nuts securing  the  handrail  (7)  to  the  platform  (23)  and  to the  base  assembly  (10)  and  remove  the  handrail. (2)   Remove   the   other   handrail   in   the   same manner. b.   Cleaning,   inspection,   and   Repair. (1)   Wash   the   parts   in   cleaning   solvent,   Federal Specification    P-D-680. (2)  Inspect handrails   for   cracks,   excessive looseness,  and  pinch  points. (3)   Weld   a   cracked   handrail. (4)   Replace   a   defective   handrail. c.   Installation. (1)   Position   the   handrail   on   the   platform   (23) and   base   assembly   (10)   and   secure   with   two   bolts (2  and  8)  and  nuts. (2)  Install  the  other  handrail  in  the  same  man- ner. 43.  GENERAL. The   base   assembly tubing. It   contains wheels   and   casters, hitch. 42. STEP ASSEMBLIES AND STAIR PLATFORM SUPPORTS. a.   Removal. (1)  Remove  the  four  bolts  (5,  figure  1)  washers, bushings,   and   nuts   securing   each   step   (6)   to   the stair  supports  (22)  and  remove  the  step. (2)   Remove   the   remaining   seven   steps   in   a similar   manner. (3)   Remove   the   platform   assembly   (paragraph 40). (4)   Remove   the   eight   cotter   pins   and   four   pivot pins   (14)   securing   the   stair   supports   to   the   base assembly   and   remove   the   supports. b.   Cleaning,   Inspection,   and   Repair. (1)   Wash   the   parts   in   cleaning   solvent,   Federal Specification     P-D-680. (2) dition. (3) (4) spots. (5) Inspect   the   steps   for   cracks   and   worn   con- Weld  any  small  cracks. Inspect   all   pivot   pins   for   excessive   wear. Inspect  the  stair  supports  for  cracks  or  weak Weld  any  small  cracks. Replace  any  defective   parts. c.   Installation. (1)   Position   the   stair   supports   (22)   on   the   base assembly   and   secure   with   four   pivot   pins   (14)   and eight  cotter  pins. (2)   Install   the   platform   assembly   (paragraph40). (3)   Position   the   step   (6)   to   the   stair   supports and   secure   with   four   bolts   (5),   washers,   bushings, and   nuts. Section VI. BASE ASSEMBLY (1)   Remove   the   two   bolts   (12,   figure   1)   and (figure   7)   is   of   welded   steel nuts   securing   the   jack   (13)   to   the   base   assembly. the   hydraulic   reservoir,   the (2)  Remove  the  other  jack  in  the  same  manner. immobilizing   jacks,   and   the (3)   Remove   the   retaining   ring   (7,   figure   3), spring   (6),   and   sleeve   (8)   from   the   base   assembly 44. IMMOBILIZING JACKS. (9). a.  Removal  and  Disassembly. (4)   Remove   the   two   bolts   (3   and   10)   that 15