BAIC Heavy Equipment Service Manual & Repair Guide PDF (EN)

SECTION 6 WORK EQUIPMENT SECTION 6 WORK EQUIPMENT Group 1 Structure and Function - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 6-1 Group 2 Operational Checks and Troubleshooting - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 6-40 Group 3 Tests and Adjustments - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 6-51 Group 4 Disassembly and Assembly - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 6-64

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SECTION 6 WORK EQUIPMENT GROUP 1 STRUCTURE AND FUNCTION GROUP 1 STRUCTURE AND FUNCTION 1. HYDRAULIC SYSTEM OUTLINE 1. HYDRAULIC SYSTEM OUTLINE The loader hydraulic system is a pilot operated, closed center system which is supplied with flow from the variable displacement piston main hydraulic pump. The loader system components are : В Main pump В Main control valve В Bucket cylinder В Boom cylinders В Remote control valve (Pilot control valve, EH type) В Safety valve Flow from the main hydraulic pump not used by the steering system leaves the steering valve (EHPS) EF port. It flows to the inlet port plate of two section or three section block type main control valve.

The main control valve is load pressure independent flow distribution system which routes flow to the boom, bucket or auxiliary cylinders (not shown) when the respective spools are shifted. Flow from the main pump is routed to the main control valve where pump outlet pressure is reduced to pilot circuit pressure. The main control valve flow to the remote control valve. The remote control valve routed flow to either end of each spool valve section in the main control valve to control spool stroke. A accumulator mounted on safety valve supplies a secondary pressure source to operated remote control valve so the boom can be lowered if the engine is off.

The return circuit for the main hydraulic system have return filter inside the hydraulic tank. The return filter uses a filter element and a bypass valve. The bypass valve is located in the upside of filter. 6-1

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2. HYDRAULIC CIRCUIT 2.

HYDRAULIC CIRCUIT 35 36 B3 S1 LH S2 Control unit 9 39 CL B.U B.I DUMP AUX 8' ELECTRONICS 3 4 2 P T 1.1 2.1 2 4 b2 B/up b2 Aux down b2 Aux up 1 3 B/in a1 Dump b1 To MCV FRONT EF P AXLE 6 L REAR 37 P 2 4 S P 32 3 1 33 PS P1 M T 31 29 A D M B 760F6WE01 1 Main pump 2 Fan & brake pump 3 Main control valve 4 RCV (EH type) 5 RCV (FNR type, opt) 6 Steering unit 7 Accumulator 8 Steering valve (EHPS) 8' Electric steering valve (opt) 9 Joystick steering lever (opt) 10 Safety valve 11 Shuttle valve 12 Boom cylinder 13 Bucket cylinder 14 Steering cylinder 15 Cut-off valve 16 Accumulator 17 Accumulator 18 Pressure sensor 19 Brake valve 20 Pressure switch 21 Hydraulic tank 22 Air breather 23 Return filter 24 By pass valve 25 Strainer 26 Oil cooler 27 Check valve 28 Pressure sensor 29 Fan motor 30 Directional valve 31 Pump motor (opt) 32 Check block (opt) 33 Pressure sensor (opt) 34 Check valve (opt) 35 Ride control valve (opt) 36 Accumulator (opt) 37 Quick coupler cylinder (opt) 38 Solenoid valve (opt) 39 Control unit 40 EH control block 41 Boom lowering valve 6-2 1 Sp.

T 3 28 PS 12 RH 28 PS a3 LS 2 pst A3 B A 4 RH 7 CR 8 L R Ps Ts LS T a2 3 T P a1 A1 B1 A2 B Floating Dump Down Bucket Boom Rollback Up b1 A2 B Aux Bucket Boom 4 Joystick b2 5 39 Control unit (Electro-Hydraulic & joystick steering) 41 40 EH18 EH17 EH20 EH19 EH22 EH21 T P 4 1 6(4) 3(2) 5(3) 2(1) ( ) : 2 Spool To MCV a3 b3 a1 b1 a2 b2 A1 B1 a2 A2 B Floating n Du Buck Rollback et Dow Boom Up Aux 2 40 LH b3 12 B.D/F 1 a2 B/Down P1 T1 A1 A1 27 27 10 16 1 R S1 B1 B2 15 S1 X1 X2 P1 T 11 X3 P PS PS T 18 28PS1 X1 X2 22 PP T1 34 23 B1 B2 2 24 25 B 21 S1 L2 L1 S2 L4L3 S 16 1 S1 B1 B2 15 P PS PS 18 PP T1 23 2 20 P2 T2 A2 6 19 17 18 S2 S3 PS G1 Parking T/M B3 18 38 PS G2 T2 26 30 S1 L2 P A B T 1 L

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HYDRAULIC CIRCUIT(DIRECT STEERING, OPT) HYDRAULIC CIRCUIT(DIRECT STEERING, OPT) Sp.

35 36 4 AUX1 BUCKET T 39 Control unit EH17 EH18 EH20 EH19 6 3 In Bucket Dump Aux Up Aux Down a3 b3 a1 b1 4 1 4 2 14 S1 LH RH 7 S2 L R FRONT T A1 20 AXLE P 18 A2 8 CF EF PS REAR PARKING 37 P T T/M 38 2 4 32 18 PS 3 1 33 PS S P P1 M T 30 29 D 31 M A B 9606WE01 1 Main pump 2 Fan & brake pump 3 Main control valve 4 RCV (EH type) 5 RCV (FNR type, opt) 6 Steering unit 7 Accumulator 8 Steering valve (EHPS) 10 Safety valve 11 Shuttle valve 12 Boom cylinder 13 Bucket cylinder 14 Steering cylinder 15 Cut-off valve 16,17 Accumulator 18 Pressure sensor 19 Brake valve 20 Pressure switch 21 Hydraulic tank 22 Air breather 23 Return filter 24 By pass valve 25 Strainer 26 Oil cooler 27 Check valve 28 Pressure sensor 29 Fan motor 30 Directional valve 31 Pump motor (opt) 32 Check block (opt) 33 Pressure sensor (opt) 34 Check valve (opt) 35 Ride control valve (opt) 36 Accumulator (opt) 37 Quick coupler cylinder (opt) 38 Solenoid valve (opt) 39 Control unit 40 EH control block 41 Boom lowering valve 6-2-1 28 13 ET BOOM 5 12 PS Joystick RH 28 PS unit draulic) EH22 EH21 40 T a2 LS a3 B A P 3 T P a1 A1 B1 A2 B2 pst A3 B3 X X X x 5 2 3spool FLOATING 3 1 2spool BUCKET )( a2 b2 To DUMP BOOM DOWN et BoomBoom MCV DownUp ROLLBACK UP X X b1 X X A2 B2 X 7 41 b2 12 b3 LH 6 4 B.D/F B.U CRAWD DUMP AUX T P 1 1 3 4 2 1.1 2.1 P1 HYD T1 B a3 LS 3 T X X P a1 A1 BUCKET DUMP B1 A2 B2 pst FLOATING )( BOOM DOWN ROLLBACK UP X X b1 41 LS 27 27 LS S1 X1 X2 11 X3 27 27 S1 P2 T2 16 1617 S1 B1 B2 S2 S3 15 C5 C6 G X2 3 C1 C3 C4 P B PS C2 1 X1 34 28PS B1 B 2 G PP T1 T2 26 2 S1 L 5 21

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