6. SWING PARKING BRAKE RELEASE R/G R/G Ps Ps Pm1 Pm2 Pm2 Pm1 P2 P1 T1,T2 T1,T2 P2 P1 Pn2 Pn1 D B A C DR P Rs CK1 NRV1 Pk BC COMP.
NRV2 S/Motor DB Pc5 D5 C5 A5 B5 Pb5 Pd5 OPTION-B BUCKET CK2 Pa5 (RG) SGo Dr SRG ARG SH DR3 C4 D4 B4 PG Pd4 0 Pc4 1 ARM1 REGENERATIION CUT OPTION-A BREAKER Pa4 Pb4 Au Dr(R7) Pc4 0 Pc3 Pc4 2 Pb3 GB GA DR2 Pa2 1 BOOM2 ARM2 Pd4 1 B(CW) Mu A(CCW) C2 D2 V3 Pb2 1 B2 A2 DR1 Pd2 Pc2 SWING BOOM1 P02 Pa2 Pb2 0 0 Pc1 D1 C1 Patt A1 Pb1 B1 P01 DR0 Pd1 TRAVEL (LEFT) TRAVEL (RIGHT) Pa1 Ptr STRAIGHT TRAVEL MRV T1 P2 P1 Pu SWING ARM BUCKET BOOM TRAVEL (2) (4) (3) (1) SH (3) (1) (2) (4) (1) (2) (3) (4) A1 A2 Psv a4 A B D E G F H J Pd2 Pc2 Pc4 0 Pa2 0 Pb2 0 T P Pa5 Pb5 Pd1 Pc1 Pb1 Pa1 Dr#,dr#,R# a2 a1 Pd4 0 Pk (T/Joint) Pm1 Pm2 Pm1 (Pump) Pm2 (Pump) A1 A1 A2 ACC Pi1 (Fl,MCV) Pi2 (Fr,MCV) A2 P2 P3 P4 PG(S/Motor) Po1(MCV) 19 M Dr a3 T(dr2) T T P1 B1 B3 A3 When the swing control lever is tilted, the pilot oil flow into SH port of shuttle valve, this pressure move spool so, discharged oil from pilot valve flow into PG port.
This pressure is applied to swing motor disc, thus the brake is released. When the swing control lever is set in the neutral position, oil in the swing motor disc cylinder is drained, thus the brake is applied. D21073HS08 3-11