TM 10-3930-669-20 2-22.  GENERAL DISASSEMBLY INSTRUCTIONS . a. Cleanliness.  Work area must be as clean as possible to prevent contamination of components.  Hydraulic components, engines, transmissions, and axles require extremely clean work area when disassembled. b. Locking Parts.  Replace all lockwire, lock washers, cotter pins, and lock nuts at time of disassembly.  Self- locking fasteners that are loosened or removed must be replaced. c. Expendable Parts.  All gaskets, packings, and seals removed during repair must be discarded and replaced with new parts. d. Removing Seals.    Be  sure  all  traces  of  oil,  gaskets,  and  sealants  are  removed  from  components.    When possible, use wood or plastic probes and scrapers to prevent damage to machined surfaces. CAUTION Do not use tape to close off fuel or oil openings.  Sticky surface of tape can mix with fuel and oil and cause engine malfunctions. e. Parts  Protection.    To   keep   dust,   moisture,   and   other   objects   out   of   internal   parts   of   the   system   or components,  cap  or  tape  over  tubes,  hoses,  air  lines,  fittings,  and  component  openings  as  soon  as  part  is  removed. Wrap all removed parts in clean paper or dip parts in preservation oil. 2-23.  GENERAL CLEANING INSTRUCTIONS . WARNING • Drycleaning  solvent  (P-D-680)  is  TOXIC  and  flammable.    Wear  protective  goggles  and gloves; use only in a well-ventilated area; avoid contact with skin, eyes, and clothes; and do not breathe vapors.  Keep away from heat or flame.  Never smoke when using solvent; the flashpoint for type I drycleaning solvent is 100'F (38°C) and for type II is 138°F (50°C). Failure to do so may result in injury or death to personnel. • If  personnel  become  dizzy  while  using  cleaning  solvent,  immediately  get  fresh  air  and medical help.  If solvent contacts skin or clothes, flush with cold water.  If solvent contacts eyes, immediately flush eyes with water and get immediate medical attention. • Never  use  fuel  to  clean  parts.    Fuel  is  highly  flammable.    Serious  personal  injury  could result if fuel ignites during cleaning. a. Cleaning Solvents.  Use only approved cleaning solvents to clean parts.  Drycleaning solvent (P-D-680) is commonly used.  Always work in a well-ventilated area. 2-489