RENR3613-01 January 2003 28 26 27 25 35 24 22 21 20 18 23 BL4 BL3 BL2 320C U Excavator Hydraulic System BL1 X AL4 AL3 AL2 APA1-UP FBB1-UP GAB1-UP MAC1-UP PAC1-UP CLM1-UP ALX1-UP CLZ1-UP AL1 TANK3 Main Conrol Valve 13 © 2003 Caterpillar All Rights Reserved PAC 47 DR2 DR6 46 T-OUT(2) T-OUT(1) PSA1 45 DR1 DR5 PSA2 Pi2 44 P-IN Pi1 DR4 P2 P1 Pilot Oil Manifold 43 Printed in U.S.A Hydraulic Schematic 171-0097 MAIN CONNECTOR LINE PILOT LINE 54 DRAIN LINE 56 PG DR 53 MU Pp3 43 44 45 46 47 Pp3 T T B 10 9 A A B B 10 A 12 13 14 17 18 19 20 21 22 23 24 25 26 27 55 36 37 38 39 40 58 61 60 11 28 31 32 33 34 35 57 59 14 SPi BP2 13 12 SP2 SDr BPi BDr BP3 SP3 SP1 T AL4 aL4 R2 BL3 18 ST BL2 aL3 AL2 AL3 BL1 20 Pi4 AL1 aL2 19 aL1 BR5 Di4 21 aR1 BR1 AR1 BR2 AR2 aR2 aR3 BR3 AR3 Pi1 aR4 AR4 22 25 24 27 26 AR5 BT R1 BP1 BR4 23 aR5 R3 28 17 15 16 DB2 DB6 DB1 PB1 PB6 PB5 29 30 DB5 A1 A2 A3 A4 A5 A6 A7 38 34 32 40 39 35 33 37 36 UP DOWN OPEN CLOSE L R IN 31 OUT PB2 HL bL4 bL3 Pi2 Di2 Pi3 Di3 bL1 bL2 DST PL PR bR1 bR2 bR4 bR3 HR Di1 bR5 A8 STANDARD COMPONENTS 50 B1 B2 B3 B4 C B5 B6 B7 Item No B8 A2 41 B1 A1 FR DR M2 G2 U B2 48 Pn2 RR P2 42 43 44 P1 P2 P1 A2 47 45 Pi1 Pi2 NO1 (SW PSA1 Ps2 59 PsM2 S3 PSA2 PAC NO3 G4 49 46 61 S1 Dr2 Dr1 G3 51 52 A B C G D F TOUT1 DR1 DR2 DR3 DR4 DR5 DR6 60 58 TOUT2 56 57 PsM1 Ps1 A1 PIN Pn1 E OUT 53 55 54 T IN Pi A3 M1 G1 Pm 62 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 Component Item No Component Bucket Control Valve 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 Boom I Control Valve 59 Left Pump Stick II Control Valve 60 61 62 Right Pump Stick Cylinder Swing Motor Travel Motor (Left) Travel Motor (Right) Anti-Reaction Valve (Swing Motor) Travel Brake Valve (Left) Travel Brake Valve (Right) Bucket Cylinder Boom Cylinders Swivel Pilot Control Valve (Travel) Stick Drift Reduction Valve Main Control Valve Boom Drift Reduction Valve Pressure Switch Pressure Switch Negavtive Flow Control Relief Valve Boom II Control Valve Stick Regeneration Valve Stick I Control Valve Swing Control Valve Left Travel Control Valve Straight Travel Control Solenoid Right Travel Control Valve Attachment Control Valve Pilot Control Valve (Swing and Stick) Pilot Control Valve (Boom and Bucket) Variable Swing Priority Valve Straight Travel Control Valve Main Relief Valve Line Relief Valve (Bucket Cylinder Rod End) Line Relief Valve (Bucket Cylinder Head End) Boom Regeneration Valve Line Relief Valve (Boom Cylinder Rod End) Negative Flow Control Relief Valve Logic Valve Pressure Switch Pilot Oil Manifold Travel Speed Solenoid Valve Swing Parking Brake Solenoid Valve Valve (Hydraulic Activation) Solenoid Valve (Hydraulic Actation) Accumulator Reducing Valve (Boom/Swing Priority Mode) Pressure Sensor (Left Pump) Bypass Check Valve Slow Return Check Valve Oil Cooler Hydraulic Tank Return Filter Case Drain Filter Pilot Relief Valve Pilot Filter Pilot Pump Pressure Sensor (Right Pump) Stick Unloading Valve Line Relief Valve (Stick Cylinder Head End) g00948176 ... Mode) Pressure Sensor (Left Pump) Bypass Check Valve Slow Return Check Valve Oil Cooler Hydraulic Tank Return Filter Case Drain Filter Pilot Relief Valve Pilot Filter Pilot Pump Pressure Sensor... Valve Pressure Switch Pilot Oil Manifold Travel Speed Solenoid Valve Swing Parking Brake Solenoid Valve Valve (Hydraulic Activation) Solenoid Valve (Hydraulic Actation) Accumulator Reducing Valve... Valve (Right) Bucket Cylinder Boom Cylinders Swivel Pilot Control Valve (Travel) Stick Drift Reduction Valve Main Control Valve Boom Drift Reduction Valve Pressure Switch Pressure Switch Negavtive