TM 5-6115-593-12 TO 35C2-3-463-1 j. Install   gasket   (4)   between   frame   and   top   of metal exhaust hose (12) and another gasket (4) on  top  of  frame  between  the  muffler  (8)  and frame. k. Install rain cap (7) on muffler (8). l. Install   eight   screws   (1),   lockwashers   (2),   and nuts (3) to secure muffler to frame and exhaust hose. m. Install    four    screws    (5)    and    front    mounting bracket, and four lockwashers (6). n. Repeat steps h.  through m.  for reassembly of other side of the exhaust system. Section X.  MAINTENANCE OF EXTERNAL POWER BOX ASSEMBLY 4-19.  GENERAL.  This section contains inspection, test, and replacement information for the external power box assembly.    See  figure  4-12  and  4-13  and  proceed  as follows: a. Inspection.  Inspect components of the external power     assembly     for     defective,     broken,     or cracked  components.    Inspect  wiring  for  loose connections. b. Testing.  Testing of components of the external power assembly is described under the appropriate  heading  in  paragraph  4-20  through 4-24. c. Repair.    Repair  by  replacement  of  components which do not function properly during testing. WARNING Set  MAINTENANCE  LOCKOUT  switch to   LOCKOUT.      Disconnect   negative cable from batteries.  Remove external power by opening EXTERNAL POWER BREAKER   CB101   and   disconnecting power  cable  from  EXTERNAL  POWER receptacle   J101.      Load   terminals   of generator    set    circuit    breaker    (CB2) may     still     be     energized     with     bus voltage. d. Replacement. If a component needs replacement,  gain  access  to  the  inside  of  the external  power  box  assembly  by  loosening  the captive   screws   and   permitting   the   panel   (4, figure 4-12) to pivot about its hinges in a forward direction.        Replace    in    step    b    (Testing)    as indicated in following paragraphs. 4-20.    PANEL  MOUNTED  CIRCUIT  BREAKER  CB101 and CB102.  (See figure 4-13.  ) a. Test. (1) Position CB101 circuit breaker (14, figure 4-13)  and  CB102  circuit  breaker  (23)  to ensure that they are in the reset position. (2) At the rear of the panel, remove terminal leads  from  one  side  of  circuit  breaker  on each circuit breaker. (3)    With an ohmmeter (Rxl scale), test circuit breakers   for   closed   contacts.      If   meter indicates  an  open  circuit  in  either  circuit breaker replace circuit breaker. (4)    Position  circuit  breakers  in  open  position. With    ohmmeter    on    same    setting,    test breakers   for   open   contacts.      If   meter indicates   closed   circuit   in   either   circuit breaker, replace circuit breaker. b. Replacement. Replace defective circuit breakers  CB101  and  CB102  (14  and  23,  figure 4-13) as follows: (1)    Removal. a. At rear of panel, tag and remove wires to CB101 and CB102. b. Remove  CB101  (14)  by  removing  screws  (12) and nuts (13). 4-38