TM    9-2320-363-20-1 Table   3-2.   ABS   Troubleshooting   (Cont) Item Action Normal  Indication Corrective   Action NOTE This  test  requires  two  people.  One  person second  person  watches  air  solenoids  and 11.   Air   Solenoid   Operation. Block   vehicle   and   release parking   brakes.   If   necessary, start   engine   and   build   air pressure   to   100   psi.   Stop engine   and   leave   ignition   switch on.   Test   each   air   solenoid   as follows: Press  buttons  13  and  A  for left   front   axle.   Push   and hold  brake  pedal  and  press START   TEST   button. Press  buttons  13  and  B  for right  front  axle.  Push  and hold  brake  pedal  and  press START   TEST   button. Press  buttons  13  and  C  for left   drive   axle.   Push   and hold  brake  pedal  and  press START   TEST   button. Press  buttons  13  and  D  for right   drive   axle.   Push   and hold  brake  pedal  and  press START   TEST   button. Digital must  push  test  buttons  and  brake  pedal  while brake  chambers  being  tested. display  will show  1  while  testing. The  digital  display should  be  between 000  to  003  after  the following  sequence has  been  observed: Push  rod  extends completely  as  air pressure  builds  in brake  chamber. Push  rod  retracts a  small  amount  as air  solenoid  releases some  air. Push  rod  retracts completely  as  air solenoid  releases air  pressure. Push  rod  starts to  extend  as  air pressure  builds  in brake  chamber. Push  rod  extends completely  as  full pressure  builds  in brake  chamber. all air l l l If  brake(s)  does  not  cycle  or digital   displays   do   not   indicate correct  numbers,  check  for: Crossed  air  solenoid electrical   leads   at   cab harness  connections. Crossed  supply  and discharge   air   lines. Tighten   or   repair   faulty wiring   (page   3-2). Replace  air  solenoid (pages  4-576,  4-578). 3-99