WARNING WARNING WARNING TM  5-6675-302-14&P b. Cleaning Inspection and Repair. Clean parts in a well-ventilated area. Avoid inhalation of solvent fumes and prolonged  exposure  of  skin  to  cleaning solvent. Wash exposed skin thoroughly. Dry   cleaning   solvent   (Fed.   Spec. P-D-680) used to clean parts is potential- ly dangerous to personnel and property. Do not use near open flame or excessive heat. Flash point of solvent is 100F to 138F (38C to 59C). (1) Clean all parts using cleaning solvent and dry thoroughly. Wipe the level vial with lens tissue or lens cloth. (2) Inspect the level vial for cracks, scratches, and broken vial tip. Inspect the mount and base for bends,  burrs  and  cracks.  Inspect  the  springs  for cracks.  Inspect  all  threaded  parts  for  worn  or defective threads. c. Reassembly and Installation. (1)  On  model  242406  refer  to  figure  5-6  and reassemble and install the circular level. On model USATS-79  refer  to  figure  5-10  and  install  the  cir- cular level. (2) Install the base plate (para 5-6). d.   Adjustment.  If  the  level  bubble  is  not centered in the vial, the circular level is out of ad- justment.  Tighten  or  loosen  the  three  adjusting screws (7, fig. 5-6 for model 242406 or 14, fig. 5-10 for model USATS-79). 5-9. Optical Plummet. a. Removal and Disassembly. (1) Remove the base plate (para 5-6). (2)  Refer  to  figure  5-7  for  model  242406,  or figure  5-8  for  model  USATS-79,  remove  and disassemble the optical plummet. b. Cleaning, Inspection and Repair. Clean parts in a well-ventilated area. Avoid inhalation of solvent fumes and prolonged  exposure  of  skin  to  cleaning solvent. Wash exposed skin thoroughly. Dry   cleaning   solvent   (Fed.   Spec. P-D-680) used to clean parts is potential- ly dangerous to personnel and property. Do not use near open flame or excessive heat. Flash point of solvent is 100F to 138F (38C to 59C). (1) Clean all metal parts with cleaning solvent and  dry  thoroughly.  Clean  lenses  and  prism  with lens tissue or a lens cloth. (2) Inspect the lenses and prism for scratches, chips,  cracks,  and  etching.  Inspect  the  housings, bracket,  mount,  milled  collar,  and  stop,  for  dents, burrs, cracks, and breaks. (3) Replace  all  defective  parts  that  cannot  be repaired. c. Reassembly and Installation. (1)  Refer  to  figure  5-7  for  model  242406  or figure 5-8 for model USATS-79, to reassemble and install the optical plummet. (2) Install the base plate (para 5-6). 5-10. Tribrach Lock Plate and Tribrach. a. Removal end Disassembly. (1) Remove the base plate (para 5-6). (2) Remove  the  leveling  screws  (para  5-7). (3) Remove  the  circular  level  (para  5-8). (4) Remove  the  optical  plummet  (para  5-9). (5)  Refer  to  figure  5-9  for  model  242406  or figure  5-10  for  model  USATS-79,  and  remove; disassemble   the   tribrach   lock   plate   from   the tribrach. b. Cleaning, Inspection and Repair. Clean parts in a well-ventilated area. Avoid inhalation of solvent fumes and prolonged exposure of skin to cleaning solvent. Wash exposed skin thoroughly. Dry cleaning  solvent  (Fed.  Spec. P-D-680) used to clean parts is potential- ly dangerous to personnel and property. Do not use near open flame or excessive heat. Flash point of solvent is 100F to 138F (38C to 59 C). (1)  Clean  all  metal  parts  using  cleaning  sol- vent and dry thoroughly. (2) Inspect the lock plate, stop plate, and lever, for  bends,  cracks,  burns,  and  excessive  wear.  In- spect  the  tribrach  for  cracks,  burrs,  and  defective casting.   Inspect   all   threaded   parts   for   worn   or damaged threads. (3)  Remove   all   burrs   and   straighten   minor bends. (4) Replace  all  defective  parts  that  cannot  be repaired. 5-7