(27)   Disconnect rupture disc to unloader control box   tube   assembly   (27,   Figure   8-39)   at rupture    disc.        Disconnect    and    remove rupture disc to compressor output pressure gauge   tube   assembly   (28,   Figure   8-39). Tag tubes for assembly reference. (28)   Unscrew  and  remove  nuts  (4,  Figure  8-7) and lockwashers (5) securing the instrument  panel  (6)  to  shock  mounts  (7). Remove instrument panel (6). (29)   Unscrew  and  remove  nuts  (2,  Figure  8-9), spacers (3, Figure 8-9) and screws (1) that hold the rupture disc. (30)   Remove  rupture  disc  assembly  (Figure  8- 9). (31)   Remove  nuts   (9)   and   screws   (8   and   16, Figure 8-7).  Remove nuts (11) and screws (10).        Separate    air    cooler    from    control panel. b. Cleaning.  Refer to paragraph 6-3.a.  for general cleaning instructions. c. Inspection.        Refer    to    paragraph    6-3.b.        for general inspection instructions. d. Repair  or  Replacement.    Refer  to  paragraph  6- 3.c. (1) Minor  nicks,  scoring  or  scratches  on  non- critical    surfaces    may    be    smoothed    with crocus cloth per Federal Specification P-C- 458. (2) Replace   all   threaded   parts   having   worn, stripped or damaged parts. e. Assembly.        To    assemble    the    Control    Panel Group, proceed as follows: (1) Position  control  panel  on  frame,  support  it and    place    air    cooler    (Figure    8-10)    in position behind control panel. Align mounting  holes.    If  removed,  place  screws (16,  Figure  8-7)  through  bar  (19).    Install washers (18) on screws (16).  Insert screws (16)   through   mounting   holes   and   attach nuts  (17).    Install  screws  (8)  and  nuts  (9, 11). (2) Place  fan  guard  (5,  Figure  8-10)  in  place over compressor shaft, remove screws (19, Figure    8-11)    from    hub    of    compressor. Attach fan (15) to hub using screws (19). (3) Position  washers  (2,  3  and  4,  Figure  8-10) and  fan  guard  (5).    Using  screw  (1)  attach fan guard (5). (4) Install    mounting    screws    (1,    Figure    8-9) through control panel side, add spacers (3) and  rupture  disc  (Figure  8-9)  onto  screws (1).  Install nuts (2).  Do not tighten rupture disc assembly at this time. (5) Install instrument panel assembly (6, Figure 8-7)   over   shock   mounts   (7).      Add   lock washer   (5)   and   install   nuts   (4).      Tighten nuts. (6) Connect   rupture   disc   to   unloader   control box   tube   assembly   (27,   Figure   8-39)   at rupture    disc    (3,    Figure    8-7).        Connect rupture disc to compressor output pressure gauge tube assembly (28, Figure 8-39). (7) Connect  rupture   disc   to   dehydrator   bleed valve    tube    assembly    (26,    Figure    8-39). Connect   mechanical   filter   to   rupture   disc tube  assembly  (25,  Figure  8-39).    Tighten nuts (2, Figure 8-9) on screws (1). (8) Assemble  control  panel  group  (Figure  8-7) to   the   air   compressor   unit   frame   using panel mounting nuts, washers and screws. (9) Place     throttle     cable     (11,     Figure     8-30) through the throttle cable hole in the control panel  from  the  front  of  the  panel.    Install cable body lock washer and hex nut, tighten nut. (10)   Install  cable  clips  (do  not  tighten).    Thread throttle  cable  wire  (11)   through   wire   stop (13,  Figure  8-30).    Assure  that  the  throttle lever   is   in   the   closed   position.      (Throttle lever    pointing    toward    fan    belt    end    of engine).    Tighten  screw  in  wire  stop  (13). Install screws and nuts for tubing clips (11) and tighten. (11)   If clutch rod bushing was removed from the control   panel,   install   and   secure.      Insert clutch rod (1, Figure 8-19) through bushing from  the  front  of  the  panel.    Install  nut  (5) and  clevis  (4)  on  rod  end.    Position  clevis (4)  over  clutch  shaft  assembly  (12),  insert clevis pin (3) and install cotter pin (2).  For clutch  rod  adjustment  see  paragraph  5-15, Section V. (12)   Connect    engine    oil    pressure    gauge    to unloader    control    box    wire    assembly    at pressure gauge (9, Figure 8-8). 6-11