(6) ing (2)  Air  Housing  Duct  Cover.  Loosen  hose  clamp and  remove  air  housing  duct  cover  (2)  by  remov- screws   (1). (3)  Shutter  Assembly.  Disconnect  wiring  to  ther- mal switch at connector plug (5) on outside of shutter assembly.   Remove   capscrews   (3)   attaching   shutter assembly  to  engine  and  blower  housing  (33).  Care- fully   pull   shutter   assembly   (4)   away   from   muffler (40)  until  lead  from  connector  (5)  to  high  tempera- ture   cutout   switch   (38)   becomes   accessible.   Discon- nect  leads  from  high  temperature  cutout  switch  (38) and  remove  shutter  assembly  (4). (4) Remove screws (33 and 34) and remove front shroud (36). (5)  Shroud  Assembly.  Open  latches  (14),  remove screws  (7),  and  washers  (8),  lift  panel  (9)  and  shroud (11) as an assembly from the engine and blower hous- ing (33). (6)   Baffles   and   Shrouds.   Remove   rear   shroud (22)  by  removing  screw  (17),  screw  (15),  washer  (16), screws  (20  and  18)  and  tie  bars  (19  and  21).  Remove baffle (25) by removing nuts (23) and J bolt (24). (7)  Blower  Grille  Assembly.  Remove  screws  (26) and  retainers  (27)  and  remove  grille  (29). (8)  Blower  Housing.  Remove  screws  (30)  attach- ing  housing  (32)  to  engine  and  remove  screw  (31)  at- taching housing to oil cooler support bracket. Remove housing (32). (9) Refer to paragraph 4-30 and remove oil oooler and  base.  Remove  screw  (33),  clip  (35),  and  remove shroud (36). c.  Cleaning  and  Testing. (1)  Inspect  the  engine  fins  and  the  housing  as- semblies  for  debris  and  remove  as  necessary.  Clean using detergent, clean cloth and brush. (2)  Disconnect  leads  and  remove  high  tempera- ture cutout switch from cylinder head. Check continuity between  two  terminals  while  heating  switch  with  its mounting stud submerged in oil. When the temperature of  the  oil  reaches  394  ±10°  F  (201  ±5°  C)  the  switch should  open.  Switch  should  close  when  temperature drops below 394 ±1O° F (201 ±5° C). If switch does not perform  as  indicated,  replace. d.  Disassembly  of  Shutter  Assembly  (see  figure 4-4). (1)  Shutter  Thermo  Power  Unit  Assembly.  Re- move   electrical   comector   (3)   by   removing   screws TM5-6115-584-12 NAVFAC   P-8-622-12 TO-35C2-3-456-1 TM-05682C-12 (1) and nuts (2). Remove screws (4) and special washer (5)  attaching  thermo  unit  assembly  (6)  to  shutter  as- sembly  and  remove  thermo  power  unit  assembly.  Be careful  plunger  does  not  fall  out  of  thermo  unit  as- sembly. (2) Shutters. Remove eight screws (7) and washers (8)  attaching  shutters  (9  and  10)  to  bracket  assem- blies  (11,  12  and  13).  Remove  shutters.  Remove  nuts (14)  washer  (15)  and  shutter  torsion  springs  (6). Brackets  (12)  can  now  be  removed.  Remove  bracket bearings  (17).  Remove  screws  (19)  and  remove  bear- ing (17) and washer (18), brackets (11 and 13). (3)  Brackets. (a)   Remove   clips   (20)   that   retain   lower   rod (21) in bracket (11) and pivot arm (22). Remove lower rod  and  bracket  (9).  Remove  bracket  bearing,  screw (19) and remove bearing (17) and washer (18). (b) Remove nut (23), clip (24) and ball arm as- sembly  (25).  Remove  bracket  (12)  and  associated bearing  (17),  washer  (18)  and  screw  (19)  using  pro- cedure as in paragraph (a) above. (c)  Remove  pivot  arm  (22)  by  removing  nut (26),  lockwasher  (27),  flatwasher  (28),  washer  (29), bearings (30) and bolt (31). e.   Test. (1)  Thermo  Power  Unit  Assembly.  Immerse  the thermo  unit  into  a  container  of  oil  while  monitoring the  oil  temperature.  Plunger  of  thermo  unit  should start to extend when temperature reaches 120°  F (49° C). Total extension at 140° F (60° C) should be at least 13/64 inch. Replace thermo unit if it does not operate properly. f.  Reassembly  of  Shutter  Assembly. (1)  Brackets. (a)  Reassemble  pivot  arm  (22)  using  bolt  (31), bearings (30), washer (29), flatwasher (28), lockwasher (27) and nut (26). (b) Mount bracket (13) to box (32) using bear- ings  (17),  lockwasher  (18),  and  screw  (19).  Be  careful not to confuse bracket (13) with bracket (12). Connect ball  arm  assembly  (25)  to  bracket  (13)  and  pivot  arm (22) using clip (24) and nut (23). (c) Mount bracket (11) along with bearing (17), lockwasher  (18)  and  screw  (19).  Ensure  that  bracket is  mounted  so  that  shutter  divider  acts  as  inside  stop. Mount  lower  rod  (21)  to  bracket  (11)  and  pivot  arm (22) using clips (21). (d) Install brackets (12), bearings (17) and lock- washer  (18).  Ensure  that  lower  bracket  is  mounted  so that  shutter  divider  acts  as  inside  stop. 4-13