TM10-3930-660-34 check valve and flows from the work port to the rod end ports of both carriage tilt cylinders.  The load compensating check valve  operation  is  the  same  as  described  in  the  MLRS  attachment  system.    Oil  pressure  unseats  the  ball  check  in  the counterbalance valve on the rod end and pushes the cylinder piston into each cylinder.  Oil in the head end of the cylinder flows from the head end port and back to the MLRS control valve.  The cylinder retracts which raises the fork tips.  Oil from the  tilt  cylinders  is  directed  to  the  MLRS  control  valve  return  circuit  and  back  to  the  hydraulic  reservoir  through  the hydraulic filter. If the electric joystick is moved to the right, the second from the top left solenoid is energized.  The oil flow through the second section is similar to the fork tips raise function but the oil flow to the tilt cylinders is reversed.  Oil flows to the head end of the tilt cylinders and pilots open the counterbalance on the rod end of the cylinders.  Oil is allowed to flow from the rod end and back to the return circuit of the MLRS valve.  The cylinders extend and lower the fork tips. A port relief valve set at 3000 psi (20685 kPa) is connected to the rod end of the tilt cylinders.  The relief valve protects the hydraulic lines from bursting when shocks or spikes are encountered on the rod side of the cylinder. The fork tips lower port relief valve is connected to the head end of the cylinders.  The relief valve is set at 725 psi (5064 kPa) to limit any external upward force on the forks. g.  Fork  Sideshift  System.    The  fork  sideshift  function,  as  with  the  previous  two  functions,  is  controlled  by  the  electric joystick and the MLRS control valve.  Hydraulic oil from the piston pump flows through the control valve as in the other two MLRS systems.  The third section of the MLRS valve controls the left fork (right cylinder) and the bottom (fourth) section controls the right fork (left cylinder). Push the button on top of the electric joystick and move the joystick to the left and the third from the top right solenoid is energized.  The solenoid allows pilot oil to flow through the solenoid and push the spool in the third section towards the left of the machine.  System oil flows through the third section, pilots open a load compensating check valve and allows oil to flow from the work port to the head end port of right cylinder which moves the left fork to the left.  Oil in the rod end of the cylinder flows back to the return circuit of the MLRS control valve. If the button is held and the electric joystick is moved to the right, the third from the top left solenoid is energized.  The oil flow  through  the  third  section  of  the  MLRS  valve  is  similar  to  the  above  left  fork  motion  but  the  flow  to  the  cylinder  is reversed.  Oil pressure is sent to the rod end port of the right cylinder which retracts the cylinder and moves the left fork t o the right. The above description of hydraulic function for the left fork can also be applied to the right fork.  The button is held down while the electric joystick is moved front to rear to control the right fork position. 16-8