9  5  0  B       S  T  E  E  R  I  N  G       S  Y  S  T  E  M TM  5-3805-258-24-1 T  E  S  T  I  N  G       A  N  D       A  D  J  U  S  T  I  N G HYDRAULIC   SYSTEM system, the hydraulic oil must be at the normal tem- perature  for  operation.  To  increase  the  oil  tempera- ture,  start  the  engine,  lift  the  bucket  and  turn  the machine  in  both  directions. NOTE:  For  more  information  on  the  pilot  system and   the   hydraulic   pump,   see   HYDRAULIC   SYS- TEM PUMP EFFICIENCY CHECK For any pump test at a given rpm, the pump flow (gpm)  at  100  psi  (690  kPa)  will  be  larger  than  the pump  flow  (gpm)  at  1000  psi  (6900  kPa). The  difference  between  the  pump  flow  of  the  two operating  pressures  is  the  flow  loss. Method of finding flow loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pump flow at 100 psi . . . . . 57.5   gpm   (liter/min)* Pump  flow  at 1000  psi . . . . . . . . . . . . . . . . . . . . . . –52.0   gpm   (liter/min)* Flow loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   5.5   gpm   (liter/min)* Flow loss when given as a percent of pump flow is used  as  a  measure  of  pump  performance. Example of finding percent of flow loss . . . . . . . . . . . gpm flow loss Percent X 100 = of flow Pump flow @ 100 psi loss *5.5 or X   100 = 9.5% *57.5 If the percent of flow loss is more than 10%, pump performance  is  not  good  enough. *Numbers  in  examples  are  for  illustration  and  are not values for any specific pump or pump condition. See  SPECIFICATIONS  for  pump  flow  of  a  new pump  at  100  and  1000  psi. Test On The Machine Install   a   Flow   Meter.   For   Formula   I,   measure pump flow at 100 psi (690 kPa) and at 1000 psi (6900 kPa)   with   engine-at   high   idle   rpm. Formula  I: gpm @ 100 psi - gpm @ 1000  psi gpm @ 100 psi loss Test On The Bench If the test bench can be run at 1000 psi and at full pump  rpm,  find  the  percent  of  flow  loss  using  For- mula  I. If the test bench can not be run at 1000 psi at full pump  rpm,  run  the  pump  shaft  at  1000  rpm.  Mea- sure the pump flow at 100 psi (690 kPa) and at 1000 psi  (6900  kPa).  Use  these  values  in  the  top  part  of Formula  II.  For  the  bottom  part  of  the  formula,  run the pump shaft at 2000 rpm. Measure the pump flow at 100 psi. Formula  II: gpm @ 100 psi - gpm @ 1000 psi Pump flow @ 100 psi @ 2000 rpm STEERING FORCE CHECK Percent X 100 =      of flow loss Check the force needed to turn the steering wheel. The  torque  must  be  as  follows: (a) (b) To  turn  the  steering  wheel  VERY  SLOW- LY  when  the  engine  is  stopped  4.0  to  4.5 N*m  (35  to  40  lb.  in.) To  turn  the  steering  wheel  VERY  SLOW- LY  when  the  engine  is  at  LOW  IDLE  2.3 to  2.8  Nom  (20  to  25  lb.  in.) STEERING   TIME   CHECK To  check  the  steering  time,  put  the  machine  on a  dry,  hard  surface.  With  the  engine  at  high  idle, the  time  for  a  full  turn,  from  stop  to  stop,  must  not be  more  than  2.5  ±  .5  second. The  difference  between  the  time  for  a  right  turn and the time for a left turn must not be more than .3 second. With the brakes activated, the time must not increase  more  than  .2  second. If the difference between the times for a full right turn  and  a  full  left  turn  is  more  than  .3  seconds: 1. 2. Remove   the   end   cover   from   steering   control valve (1 ). Add flow balance shims (2) to decrease the right turn time (steer faster) and increase the left turn time (steer slower). If the flow balance shims are removed,  the  result  is  opposite. Percent X 100 =      of flow 4-53