1) 1) SERVICE BRAKE RELEASED (OLD) SERVICE BRAKE RELEASED (OLD) 24 FRONT P1 A1 45 T1 P2 T2 A2 25 21 22 21 REAR 20 S2 B2 B1 S1 S3 23 C5 C6 C3 G1 PS P B3 C4 C1 46 G2 PS T/M PARKING T2 23 Return line P 6 Return line A B D L S1 B A Main pump 955A4BS02 When the pedal of brake valve (24) is released, the operating force is eliminated by the force of the spring, and the spool is returned. When the spool removes up, the drain port is opened and the hydraulic oil in the piston of axles return to the tank (26). Therefore, the service brake is kept released. 4-4 T1 27 6 8