SERVICE MANUAL ports are needed with all sizes of tubing except 1/8" O.D. if compression-type fittings are used. Once  the  tubing  has  been  connected  and  tightened the  sleeve  has  been  crimped  on  the  tubing  and  insert. Since the sleeve has been compressed and distortion of the   insert   may   have   resulted,   the   sleeve   and   inserts should never be used the second time. To assemble tubing ends for use with compression- type   fittings,   the   following   steps   should   be   followed carefully. 1. Loosen and remove nut from fitting. 2. Pull tubing from fitting. 3. Repeat   the   same   operations   at   other   end   of tubing.    If  only  one  end  of  line  needs  repairing, second  end  need  not  be  disconnected  if  line  is long enough to permit repairing. 4. Cut  the  selected  size  of  tubing  to  length.    Be sure   to   make   smooth,   square   cuts.      Either   a sharp knife or hack saw may be used. 5. Position nut on tube. 6. Position compression sleeve on tube. *7. Insert tube support into tube. *8. Position   the   tube,   support   and   sleeve   in   the fitting. Push tube in fitting until it bottoms. 9. Then   install   and    tighten    tube    nut    to    secure sleeve on tubing. 10. Inspect tubing connections for air leakage.  With the tubing and associated fittings charged to full system air pressure coat tubing lines and fittings with soap suds to check for leakage. No leakage is   permissible.   Leakage   at   a   tubing   fitting   is sometimes   corrected   by   tightening   the   tubing fitting   nut.   If   this   fails   to   correct   the   leakage, replace the tubing fitting, tubing, or both. * No tube support is used with 1/8" O.D. tubing.  Certain fittings used in accessory piping systems have the tube support  as  an  integral  part  of  the  fitting  body.  These fittings   may   be   reused   if   no   distortion   of   the   tube support has occurred. NYLON TUBING SPECIAL INSTRUCTIONS For   the   present   this   nylon   tubing   should   not   be substituted in the field for any metallic tubing. In addition, the  following  precautions  must  be  taken  in  the  use  of nylon tubing. Fig. 6 Nylon Tubing Assembly 1Fitting 2Tube Support or Insert 3Sleeve 4Short Nut 5Long Nut 6Nylon Tubing 1. Do not use nylon tubing for any application which would  cause  it  to  be  exposed  to  temperatures below  -40  degrees  C  or  +I  11  degrees  C  (-40 degrees F or above +200 degrees F). 2. Do not subject nylon tubing to working pressure in excess of 1034 kpa (150 psi). 3. Do    not    use    nylon    tubing    for    frame-to-axle, tractor-to-trailer  or  any  similar  line  where  a  high degree of flexibility is required. 4. Observe extreme care when welding near nylon tubing.  Hot slag or spark will damage the tubing. 5. Protect nylon tubing from battery acid. Fig. 7 Nylon Tubing Assembly Cross Section 1Fitting 2Short Nut 3Nylon Tubing 4Sleeve 5 Tube Insert or Support CTS-4079 - CHAPTER XII - Page 5