p.  Fill  hydraulic  system  with  hydraulic  oil  MIL- slotted  adjustment  control  screw  (34)  to  obtain  a H-5606. pressure of 320 ± 10 psi. q.  Start  the  engine.  (Refer  to  Operator  and Organizational   Maintenance   Manual). s.  Replace  hex  cap,  shut  down  engine,  drain  hy– draulic  system,  remove  pressure  gauge,  connect Remove the hex cap (11, fig. 14-5) and washer hydraulic  output  line  to  pump,  and  refill  system  with (12) located on top of the pump housing, and adjust the hydraulic  oil,  MIL-H-5606. Section IV. SPEED SWITCH, TACHOMETER DRIVE AND ADAPTER 14-17.   General. a.  The  speed  switch,  driven  by  the  camshaft through  a  tachometer  drive  assembly  and  an  angle adapter,  provides  sequenced  control  of  circuits  during engine  startup  and  protection  against  engine  overspeed during  operation.  Three  sets  of  contact  elements,  S9–1, S9-2,  and  S9–3,  contained  in  the  speed  switch,  are  set to  open,  close,  or  transfer  by  centrifugal  force  at  certain engine  speeds.  The  speed  switch  drive  gear  is  designed to  drive  the  speed  switch  at  one–half  engine  speed b.  At  an  engine  speed  of  580  to  620  rpm  (acceler- ating)  element  S9–1  transfers  two  sets  of  contacts, energizing  the  field  flash  circuit  and  de-energizing  the crank  relay  to  stop  the  starting  motor. On  Class  1  sets,  when  the  engine  reaches  the speed range of 1180 to 1220 rpm (Mode I); 1650 to 1700 rpm (Mode H) element S9–2 closes, energizing the electro-hydraulic  governor  which  takes  over  control  of engine speed. d.  Speed  switch  element  S9-3  consists  of  two  sets of  contacts  which  are  set  to  transfer  at  an  engine  speed of 2425 ± 25 rpm to shut down the engine and prevent damage  to  the  equipment.  Shutdown  is  achieved  by de-energizing  the  stop-run  relay  and  the  fuel  solenoid, cutting off fuel to the engine. 2. Elements  S9–1  and  S9–2  reset  at  100  rpm  (de- creasing)  below  actuation  speed.  Element  S9–3  is manually  reset  by  a  pushbutton  on  the  speed  switch housing. 14–18.  Speed  Switch  Removal. Refer  to  Operator  and  Organizational  Maintenance Manual for removal of the speed switch. 14-19.  Speed  Switch  Tests,  Adjustment,  Repair  and Installation. a.  Connect  a  variable  speed  drive  device  to  the speed  switch  drive.  The  drive  device  must  have  a tachometer  in  order  to  determine  the  speed  of  the  device in  rpm’s. b.  With  an  ohmmeter  on  the  R1  scale,  reading from the speed switch connector, check for the contact conditions  of  elements  S9–1,  S9-2,  and  S9-3  illustrated in figure 14-6. c.  When  contact  conditions  are  verified,  as  shown in  figure  14-6,  start  variable  drive  and  gradually increase  speed,  with  ohmmeter  connected  to  pins  B  and A. At a speed of 300 ± 15 rpm, the ohmmeter should indicate  that  contact  A–B  opens.  Hold  the  variable speed  drive  at  that  speed  and  transfer  the  ohmmeter leads  to  pins  A  and  C.  The  ohmmeter  should  indicate  a closed contact. d.  Leave  the  ohmmeter  leads  connected  to  pins  A and  C  and  gradually  reduce  speed.  In  the  range  of  190 to 210 rpm, the contacts of element S9–1 should reset to the  condition  illustrated  in  figure  14–6.  To  verify operation  of  element  S9-1  contacts  A  and  C,  increase drive  speed  gradually  and  observe  that  the  contacts close at 300 ± 15 rpm range. e.  Connect  ohmmeter  leads  across  pins  D  and  E and  verify  an  open  circuit.  Increase  drive  speed  and observe that element S9–2 (contacts D and E) closes in the speed range of 600 ± 20 rpm (Mode I); 840 ± 20 rpm (Mode II). Gradually reduce speed to 490 minimum rpm (Mode I); 725 minimum rpm (Mode II). Observe that element  S9–2  resets  to  the  condition  shown  in  figure 14-6. NOTE (Required  for  P/N  70-1105-3  and  P/N  70- 1105-4  switches  only)  In  order  to  bench check the trip speeds, apply +24VDC to terminals  E  and  G  of  the  MS3102R–18-1P connector  with  the  case  negative. f.  Connect  ohmmeter  across  pins  H  and  G  and verify  a  closed  circuit.  Increase  drive  speed  gradually. The contacts should open at a speed of 1200 to 1250 rpm.  Hold  drive  speed  and  read  contacts  F  and  J. Meter  should  indicate  a  closed  circuit.  Reduce  drive speed  to  less  than  1000  rpm,  press  the  manual  reset switch  and  observe  with  the  meter  that  element  S9–3 contacts reset to the condition shown in figure 14–6. g.   To   obtain   the   required   performance   character– istics  during  tests  c  through  f  adjustments  can  be  made. By loosening screws (1, figure 14-7) and rotating the cap and cover assembly relative to the body assembly, the  trip  points  of  all  three  elements  can  be  raised  or lowered.  In  addition,  the  trip  speed  of  each  individual element can be raised or lowered by removing cover screws  as  shown  in  figure  14-6  and  turning  appropriate set screw located beneath cover screws with a 1/16 inch allen   wrench. Change   11   14-9