SERVICE MANUAL 3. Turn  vehicle  wheel  and  at  the  same  time  rotate adjusting    screw    until    brake    shoes    are    tight against drum. 4. Back off adjusting screw just enough to eliminate drag. 5. Make and hold full brake application to fully seat brake  shoes  against  drum  and  note  the  angle between slack adjust  and  push  rod.    This  angle should be a minimum of 90 degrees or more. If  the  foregoing  adjustment  or  relining  of  brake  shoes does not establish an angle of near 90 degrees between push rod and slack adjuster with brakes applied (Fig. 2), then  maximum  force  against  slack  adjuster  cannot  be obtained.  Readjust push rod as follows: 1. Disconnect slack adjuster and push rod.  Do this carefully  because  slack  adjuster  may  be  turned toward brake chamber with considerable pressure. Fig. 2  Brake Chamber and Slack Adjuster A Slack Adjuster More Than 90° in Released Position B Applied Position C Angle Should be 90° in Applied Position 2. Loosen lock nut on clevis and thread clevis onto push   rod   toward   brake   chamber   for   several turns. 3. Reconnect   slack   adjuster   and   push   rod   with clevis pin. 4. Make  a  full  brake  application  and  check  angle between  slack  adjuster  and  push  rod.    If   90 degrees  or  slightly  more  is  not  obtained  with brakes  applied,  repeat  adjustment  until  angle  is satisfactory. The  desirable  situation  is  to  bring  brake  shoes  against drum   just   as   the   slack   adjuster   attains   the   near   90 degree position (Fig. 2). MANUAL SLACK ADJUSTER OPERATION TEST Slack adjusters should rotate freely without binding when the   brakes   are   applied   and   when   the   brakes   are released, all slack adjusters must return to the released position freely and without binding.  The slack adjusters must  be  adjusted  so  that  the  angles  formed  by  brake chamber   push   rod   and   center   of   slack   are   near   90 degrees as described in BRAKE ADUSTMENT. BRAKE CHAMBER SERVICE TEST Operational Test Apply   and   release   the   brakes,   observing   the   brake chamber push rod.  The chamber push rod should move out  promptly  and  return  to  the  released  position  freely without binding. Leakage Test 1. Apply the service brakes and apply soap solution to  the  chamber  clamping  area.    If  leakage  is noted, tighten the clamp ring bolts and if leakage does   not   stop,   the   chamber   must   either   be reconditioned or replaced. 2. With   the   service   brakes   applied,   check   for leakage  through  the  diaphragm  by  applying  a soap solution to the push rod opening and drain holes  on  non-pressured  side  of  chamber.    No leakage  is  permissable.    If  leakage  is  evident, the chamber diaphragm must either be replaced or complete chamber replaced. LUBRICATION Brake    camshafts    and    slack    adjusters    should    be lubricated   every   five   months   or   26,000   km   (16,000 miles).      Refer   to   LUBRICATION   Section   for   type   of lubricant.  Do not overlubricate.  Slack adjusters without fittings    require    no    lubrication.        The    provision    for lubrication  may  differ  on  slack  adjusters.    Some  have zerk fittings while others utilize pipe plugs or snap-in type plugs or covers. When brake linings are replaced, apply a thin coat of the same    lubricant    to    brake    shoe    anchor    pins    and camshafts.  Do not overlubricate. CTS-4080W - Page 4