TM 10-3930-659-10 1-12.  SERVICE BRAKE SYSTEM (Con’t). f.  Parking Brake.  The parking brake mechanism is mounted on the front of the transmission.  The actuating pedal and release handle is located in the operator’s cab.  A red light flashes and an audible alarm sounds if the parking brake is applied while the engine is running and the transmission is In gear; a yellow light flashes if the parking brake is applied and the transmission is in N (Neutral). 1-13.  STEERING SYSTEM. a.  General.  The steering system is a full-time power assist-type.  A secondary electrically operated pump Is included to provide emergency steering.  The other components of the system are the steering valve, cylinders, and crossover relief valve. b.  Steering Hydraulic Pump.  The steering hydraulic pump supplies the steering system only.  It is mounted on the back of the transmission and is driven by the engine.  It is a fixed displacement, external gear-type pump. c.    Secondary  Steering  Pump.    The  secondary  steering  pump  is  electrically  powered.    It  operates  when  the  key switch is on and low steering system pressure Is sensed by a pressure switch. 1-14.  FORKLIFT HYDRAULIC SYSTEM. a.  General.  The forklift hydraulic system includes the service brake system,  steering system, hydraulic reservoir, and attachment  components.    The  service  brake  and  steering  systems  are  described  in  paragraphs  1-12  and  1-13.    The attachment components consist of the attachment control valve, oil cooler, and two oil filters. b.  Hydraulic Reservoir.  The hydraulic reservoir is a 20 gl (76 1) tank, located just ahead of the engine. c.  Attachment Control Valve.  The attachment control valve controls the operation of the forks for boom raise and lower, tilt, and spacing. d.  Oil Cooler.  The oil cooler is mounted alongside the engine radiator and cools both the hydraulic system oil and the transmission oil In separate sections. e.  OI Filters.  There are two filters that are contained in the hydraulic system.  The pump suction filter, located at the hydraulic reservoir, filters larger contaminates and uses a washable screen.  The return filter combines a bypass valve and contains  a  replaceable  cartridge-type  filter.    It  filters  contaminants  entering  the  reservoir  from  the  components  of  the system.  Should the return filter become clogged, a warning indicator will light and the bypass valve will open. 1-15.  ELECTRICAL SYSTEM. a.    Charging  System.    The  24-volt  charging  system  consists  of  the  batteries  and  an  alternator  with  an  internal regulator. 1-11