SERVICE MANUAL 4. Remove  fittings  from  valve.    Mark  these  fittings also. 5. Remove valve from chassis. a. Suspended Pedal Valves Remove    nuts    on    exterior    side    of    dash    and remove valve assembly. b. Treadle Type Valves Remove  brake  valve  and  treadle  assembly  by removing three capscrews on outer bolt circle of mounting plate.Basic valve alone may be removed by  removing  three  capscrews  on  inner bolt circle. REINSTALL Installation   of   brake   valve   is   basically   the   reverse   of removal.        Be    sure    to    make    service    checks    before returning vehicle to service. DISASSEMBLY Treadle Type Brake Valve (E6) Refer to Fig. 8 for numbers in parenthesis. 1. If  the  entire  brake  valve  and  treadle  assembly was removed from the vehicle, remove the three capscrews securing  the  treadle  assembly  to  the basic brake valve. 2. Remove screw (1) securing the exhaust diaphragm  (3)  and  washer  (2)  to  exhaust  cover (4). 3. Remove  four  screws  that  secure  exhaust  cover (4) to lower body (10). 4. Remove    secondary    inlet    and    exhaust    valve assembly  (items  5  through  9)  from  lower  body. Disassembly   of    secondary    inlet    and    exhaust valve  assembly  is  not  required  since  it  is  only serviced as an assembly. 5. Remove  four  hex  head  capscrews  securing  the lower body (10) to upper body (11) and separate the bodies. 6. Remove the rubber seal ring (12) from the lower body. 7. Apply thumb pressure to primary  piston  (16),  lift out  and  up  on  the  three  lock  tabs   of   primary piston retainer (19). 8. Using a 10 mm (3/8") wrench, hold ENSA nut on threaded  end  of  stem  on  top  of  primary  piston. Insert a screwdriver in exhaust passage through center  of  valve  and  engage  slotted  head  of  the stem (23). CAUTION Before  proceeding  with  the  disassembly (refer to Fig. 8), note the ESNA nut and stem are used to contain primary piston return  spring  (17),  stem  spring  (21)  and relay piston spring (14).  Combined force of these springs is approximately 222 N (50  lbf)  and  care  must  be  taken  when removing  the  ESNA   nut   as   the   spring forces will be released. It is recommended   that   primary   piston   and relay piston be manually or mechanically contained  while  nut  and  stem  are  being removed to prevent bodily injury. 9. Rotate    the    screwdriver    counterclockwise    and remove stem (23), stem spring (21), spring guide (22) and ESNA nut. 10. Remove   relay   piston   (13),   relay   piston   spring (14),   primary   piston   and   primary   piston   return spring from the upper body. 11. Disassemble    primary    piston    by    rotating    the spring  seat  nut  (24)  counterclockwise.  Separate spring  seat  nut,  spring  seat  (20),  rubber  spring (18) and remove piston O-ring. 12. Remove   large   and   small   O-rings   from   relay piston. 13. Remove retaining ring securing primary inlet and exhaust  valve  assembly  (15)  in  upper  body  and remove  valve  assembly.     Do   not   disassemble primary    inlet    as    it    is    only    serviced    as    an assembly. CLEANING AND INSPECTION Wash  all  metal  parts  in  cleaning  solvent  and  dry  them. Inspect   all   parts   for   excessive   wear   or   deterioration. Inspect valve seats for nicks or burrs.  Check springs for cracks  or  corrosion.    Replace  all  rubber  parts  and  any part not found to be serviceable during inspection. ASSEMBLY Treadle Type Brake Valve (E6) Prior  to  reassembling  brake  valve,  lubricate  all  O-rings, O-ring grooves, piston bores and metal-to-metal moving surfaces with Item 1 in LUBRICANT SPECIFICATIONS. Refer  to  Fig.  8  for  numbers  in  parenthesis.  All  torque’s specified are assembly torque’s and can be expected to differ  after  assembly  is  accomplished.    Do  not  retorque after initial assembly. CTS-4079 CHAPTER IV - Page 7