TM 10-3930-669-20 2-23.  GENERAL CLEANING INSTRUCTIONS (CONT. ). WARNING Compressed  air  used  for  cleaning  purposes  will  not  exceed  30  psi  (207  kPa).    Use  only  with effective chip guarding and personal protective equipment (goggles/shield, gloves, etc.). b. Removing Deposits.  Soak parts in drycleaning solvent (P-D-680) and wash away deposits by flushing or spraying.  When necessary, brush with a soft-bristle brush (not wire) moistened in solvent.  Use compressed air to dry parts, except bearings, after cleaning.  Bearings must drip and air dry. c. Tools.  Do not use wire brushes, abrasive wheels, or compounds to clean parts unless specifically approved in the detailed procedures.  Parts may be scratched or altered and may be weakened. d. Ball and Roller Bearings.  When cleaning ball or roller bearings, place them in a basket and suspend them in  a  container  of  drycleaning  solvent  (P-D-680)  .    If  needed,  use  a  brush  to  remove  caked  grease,  chips,  etc.    Avoid rotating  bearing  before  solid  particles  are  removed  to  prevent  damage  to  precision  bearing  surfaces.    When  bearings have been cleaned, coat them lightly with lubricating oil to remove solvent. CAUTION Do not clean tires, lubricant seals, rubber hoses, or electrical components with solvent mixture. e. Rubber Parts.  Do not clean preformed packings or rubber parts in drycleaning solvent.  Wipe parts clean with a dry, cleaning cloth. WARNING Steam  cleaning  creates  hazardous  noise  levels  and  severe  burn  potential.    Eye,  skin,  and  ear protection is required.  Failure to comply may result in injury to personnel. f. Exterior Parts.  Steam clean all exterior parts thoroughly before removing.  This will make inspection and disassembly easier. WARNING Solvents used with a spray gun must be used in a spray booth with filter.  Face shield must be used by personnel operating spray gun.  Failure to comply may result in injury to personnel. g. Engine,  Cab,  and  Body.    Use  a  spray  gun  and  solvent  mixture  for  cleaning  exterior  of  engine,  cab,  and body.  Allow mixture to remain on item for ten minutes before rinsing.  Rinse with hot water under 80 to 120 pounds of pressure,  if  available.    An  ordinary  garden  hose  with  nozzle  may  be  used  if  other  equipment  is  not  available.    Rinse thoroughly. 2-490