TRUCK SERVICE MANUAL TM 5-4210-230-14&P-1 BODIES AND CABS 7. Pressure    test    air    conditioning    system    to    check performance.      (See   "Air   Conditioning   Performance Check".) 8. After pressure test is completed disconnect manifold gauge hoses from compressor service ports.  Install cap on compressor suction service port.  Install cap or     fan     drive     override     switch     (if     equipped)     on compressor discharge service port. 9. Close hood and cab doors. ADDING REFRIGERANT TO AIR CONDITIONING SYSTEM When     the     air     conditioning     system     is     low     on refrigerant,   it   can   be   refilled   using   the   SE-2443   Portable Service  Station  and  SE-2448  Heated  Charging  Cylinder  as outlined below. 1. Raise hood. 2. Connect SE-2443 Service Station to air conditioning system service ports as follows: a. Close  manifold  suction  and  discharge  valves (turn fully clockwise). b. Remove cap from compressor suction service port.  Connect manifold suction gauge hose to compressor suction service port. c. Remove   cap   or   engine   fan   drive   override switch (if equipped) from compressor discharge   service   port.      Connect   manifold discharge gauge hose to compressor discharge service port. 3. Fill SE-2448 Charging Cylinder with 2.5 kg (5 lbs.) of refrigerant. (Follow equipment manufacturer's instructions.)    Make    sure    all    valves    on    charging cylinder are closed after filling. 4. Connect  service  hose  from  center  manifold  fitting  to valve on top of charging cylinder. 5. Open   refrigerant   supply   valve   on   top   of   charging cylinder. 6. Loosen  service  hoses  at  compressor  service  ports. Open  gauge  valves  and  allow  refrigerant  to  escape for  10  seconds  to  purge  air  from  hoses.    Tighten hose connections.  Close gauge valves. 7. Set   air   conditioning   controls   for   maximum   cooling (A/C   lever   at   "COLD",   blower   switch   on   "HIGH"). Open both cab doors. 8. Operate  engine  at  RPM  specified  in  "Engine  Speed Chart" under SPECIFICATIONS. 9. SLOWLY open suction gauge valve to add refrigerant to system.  Do not allow liquid refrigerant to  enter  compressor.    Observe  sight  glass  and  add refrigerant until no frothing or bubbles appear in sight glass. Continue adding refrigerant until .5 kg (1.1 lbs.) has been added to system after sight glass has cleared. Do not overcharge system. 10. Close   suction   gauge   valve   and   close   refrigerant supply valve on top of charging cylinder. 11. Pressure   test   air   conditioning   system.      (see   "Air Conditioning Performance Check".) 12. After pressure test is completed, disconnect manifold gauge hoses from compressor service ports.  Install cap on compressor suction service port.  Install cap or     fan     drive     override     switch     (if     equipped)     on compressor discharge service port. 13. Check  air  conditioning  system  for  refrigerant  leaks using an electronic leak detector.  Follow equipment manufacturer's instructions. 14. Close hood and cab doors. COMPONENT REMOVAL AND INSTALLATION IMPORTANT Certain  precautions  must  be  observed  when servicing  the  air  conditioning  system.    (See SAFETY   PRECAUTIONS   and   also   "Service Hints" below.) SERVICE HINTS Special     attention     to     the     following     items     while performing    component    removal,    installation    and    service operations     will     aid     in     avoiding     unnecessary     and     time consuming problems. 1. Note    control    cable    routings    during    removal    and reroute   cables   carefully   in   the   same   path   when installing. Where    necessary    cables    should    make    gradual, sweeping   curves.      Sharp   directional   turns   tend   to increase  resistance  to  bowden  wire  movement  and sometimes    cause    kinks    which    render    the    cable inoperative. CTS-2731   Page 24 PRINTED IN UNITED STATES OF AMERICA