TM 10-3930-664-24 1-18. BRAKING SYSTEM.  (Figure 1-12) a. Service brake.  Fully depressing the brake and inching pedal applies four hydraulic disc brake assemblies located inside the front and rear axles.  Separate disc brake assemblies are associated with each wheel.  Releasing the pedal relieves the hydraulic pressure and allow the wheel to spin freely.  When the pedal is depressed the service lights or blackout  light  will  illuminated  depending  on  the  position  for  the  vehicular  lights  switch.    Hydraulic  pressure  to  the  brake assemblies is produced in the master cylinder.  Two separate hydraulic circuits, each with a master cylinder, are used for front and rear breaks.  Should one of the hydraulic circuit develop a leak the other will remain functional to stop the vehicle. This safety feature will reduce the risk of a total brake failure. b. Parking  Brake.    The  parking  brake  is  controlled  by  a  two-position  toggle  switch.  Placing  switch  in  ON position  causes  a  spring  actuated  cylinder  to  apply  the  two  front  axle  disc  brake  assemblies.    This  prevents  the  front wheels form turning.  Along with applying the brake assemblies, the transmission speed range and directional selector are disabled preventing the vehicle from engaging in drive.  Placing the switch in the OFF position releases the parking brake. 1-19. ELECTRICAL SYSTEM.  (Figure FO-2) a. The  electrical  system  operates  on  24  VDC  and  is  charged  by  the  engine  driven  alternator.    Placing  the ignition switch in the START position will power the engine starter to  crank  the  engine.    Once  the  engine  is  running  the ignition  switch  is  released  and  remains  in  the  ON  position.    The  hourmeter  operates  only  when  the  engine  is  running. When  the  ignition  switch  is  in  the  ON  position,  the  ammeter,  engine  oil  pressure  gauge,  engine  temperature  gauge, transmission  temperature  gauge,  and  fuel  level  gauge  are  operational.    Forklift  lights  and  wind  shield  wiper  will  also functional.  If the engine fails to start when air temperature is below 32°F, the COLD START push button may be utilized to inject ether as a starting aid. b. Front and rear flood lights are controlled by two-position toggle switches.  The flood lights provide work area illumination  during  non-blackout  operations.    The  vehicle  lights  switch  assembly  provides  control  of  the  forklift  lighting functions.  Warning indicators are provided to assist the operator in isolating forklift malfunctions.  All the warning lights will illuminate when the ignition switch is placed in the ON position without the engine running.  The front differential lock is operated using the FRONT DIFF LOCK switch.  Placing the FRONT DIFF LOCK switch in the on position engages the front differential mechanism while the OFF position disengages.  The engine and all forklift power is shut down by placing the ignition switch in the OFF position. 1-31