6. SWING PARKING BRAKE RELEASE ARM CYLINDER BUCKET CYLINDER BOOM CYLINDER TRAVEL MOTOR Pi2 MU Pi1 SH AU PG DR R/G MB MA MU (CW)VB VA(CCW) PAb1 P04 RCV PEDAL P T TRAVEL P1 P2 Pu (4) (1) (2) (3) SWING ARM BUCKET BOOM P T PAtr PCtl PDtl PBtr P T Dr#, dr# A2 PUMP A1 PUMP PILOT PUMP (4) (1) (2) (3) (4) (1) (2) (3) P03 (MCV) A5 P (T/Joint) Pu (MCV) A1 A2 A3 a b d e f g h j A H G F E D B J Psv(Pump) P3 P2 PG(S/Motor) P4 P01(MCV) HYDRAULIC TANK PCsp PAk PDs PCs PCa h2 PS d1 c e2 PS PAb1 PBb1 h1 PS T P1 P(2-EPPR valve) PS PS PS PDa PBk LINE FILTER 330S3HC07 When one of the RCV lever (except travel lever) is tilted, the pilot oil flows into SH port through main control valve.
This pressure moves spool of the swing brake valve so, discharged oil from pilot valve flows to swing motor PG port. This pressure is applied to swing motor disc, thus the brake is released. When all of the RCV lever (except travel lever) are set in the neutral position, oil in the swing motor disc cylinder is drained, thus the brake is applied.
3-12 RV2 Cck Bk Ak BC1 N RV2 Cck DR9 Co P05 Do PCo PDo OPTION Ca BC2 NRV1 Cco CoR DoR AkR LCk1 LCk2 P04 PBk PAk PCbc PBa2 PAa2 DR6 P02 PBa Abk PBrc PAbk DR4 Bb Ab LCo CaR BUCKET BbkR PBa PCa PDa PAa2 P P Da DR7 CRa PaL ARM1 DaR LCa BbkR LCa2 ARM2 PAa2 DR6 P02 Csp Db2 BOOM2 Ccb SWING P/R LCar LCbk BbR ARM REGEN Cs Ds PCs PDs DR5 SWING LCs AbR LCb CRb BOOM1 P03 DR3 Ctl Dtl PCtl PDtl Patt (RIGHT) TRAVEL DR1 BtR AtR (RIGHT) TRAVEL (LEFT) TRAVEL MRV