Hydraulic System - Case CX75SR TIER 3 Service Manual

Lighting
Working light
Interior light
Horn
Other
Wiper with intermittent function, window washer, air conditioner, rear view mirrors, clock

Hydraulic system

Hydraulic pump drive system, direct engine link (no transmission)
Main pump
Manufacturer ...................................................................................................................................... Bosch Rexroth
Pump type ........................................................................................double variable displacement piston pump x 1
Gear pump ........................................................................................................................................................... x 2
Gear pump (for blade use) ........................................................................................................................ 24.2 L/min
Displacement volume ..................................................................................................34.0 cm
Operating pressure Rated .................................................................................................... 29.4 MPa (4264.11 psi)
Input revolution speed Rated................................................................................................. 2000 min-1 (2000 rpm)
Maximum input revolution speed ........................................................................................... 2250 min-1 (2250 rpm)
Maximum discharge flow ........................................................68 x 2 L/min at 2000 min-1 (18 x 2 gpm at 2000 rpm)
Pilot pump
Pump type ................................................................................................................Fixed displacement gear pump
Displacement volume ......................................................................................................... 10.7 cm
Operating pressure........................................................................................................................ 4.2 MPa (610 psi)
Maximum flow.................................................................................................... 21.4 L/min (5.6 gpm) at 2000 min-1
Gear pump (for blade)
Pump type ................................................................................................................Fixed displacement gear pump
Displacement volume .......................................................................................................................... 12.1 cm
Operating pressure.................................................................................................................... 22.6 MPa (3280 psi)
Maximum flow.................................................................................................... 24.2 L/min (6.4 gpm) at 2000 min-1
Control method
Full hosepower angle control in concurrence.
Horsepower control by blade pump operation pressure.
Set pressure of main relief valve
Boom/Arm/ Bucket/Travel .................................................................................................... 29.4 MPa (4264.11 psi)
Swing.................................................................................................................................... 22.6 MPa (3277.85 psi)
Blade .................................................................................................................................... 22.6 MPa (3277.85 psi)
Set pressure of overload relief valve
Boom/Arm/ Bucket............................................................................................................... 31.9 MPa (4626.70 psi)
Blade .................................................................................................................................... 25.5 MPa (3698.46 psi)
Control Valve
Model; Double spool x 1 Quintuple spool x 2
Operation method: hydraulic pilot method: travel, swing, blade and operating machine
Maximum flow
Mono Boom with blade ................................................................................... 75.8 L / min (20 gpm) (at 2230 min-1)
Offset Boom with blade (CX75SR) .............................................................. 75.2 L / min (19.8 gpm) (at 2320 min-1)
Overload set pressure
Other:
Mono Boom with blade .......................................................................... 31.9 ± 0.3 MPa (4630 ± 44 psi) at 20 L/min
Offset Boom with blade (CX75SR) ........................................................ 31.9 ± 0.3 MPa (4630 ± 44 psi) at 20 L/min
Boom (CX80):
Swing right ........................................................................................ 33.3 ± 0.3 MPa (4830 ± 44 psi) at 20 L/min
Swing left .......................................................................................... 31.9 ± 0.3 MPa (4630 ± 44 psi) at 20 L/min
Boom up/down (CX75SR)
Mono Boom with blade ..................................................................... 25.5 ± 0.3 MPa (3700 ± 44 psi) at 20 L/min
Offset Boom with blade..................................................................... 25.5 ± 0.3 MPa (3700 ± 44 psi) at 20 L/min
Offset right (CX75SR)
Offset Boom with blade..................................................................... 31.9 ± 0.3 MPa (4630 ± 44 psi) at 20 L/min
Lep SC75SRCX80-1002-0NA
Cab top: 24V, 55W (x1)
Boom up: 24V, 70W (x1)
24V, 6W (x1)
Electric horn x2
1002-13
3
(2.07 cu in) x 2 /rev
3
(0.65 cu in)/rev
3
/ rev
Issued 03-08