SkyTrak 6042 Service Manual - Manual (Page 243)

8.11 Model 6042 Legacy Origin 7/02
Hydraulic System
Engine Information
Idle. . . . . . . . . . . . . . . . . . . . . . 1,050 ±50 rpm
Full Speed . . . . . . . . . . . . . . . 2,750 ±100 rpm
Hydraulic Oil Information
Oil Type - 10W, meet ISO Grade 46
Capacity - Reservoir . . . . 32.2 gal. (122 liter)
Capacity - System . . . . . . . . 57 gal. (216 liter)
Note: To adjust relief settings, pressure reducing
settings or standby pressure, turn the
adjustment screw clockwise to increase
pressure or counterclockwise to decrease
pressure.
The hydraulic oil temperature for the pump flow
test should be between 100-120° F (38-49° C)
(tank hot to the touch) during testing.
Equipment Needed to Perform Tests
from Hydraulic Diagnostic Test Kit
Circuit Gauge Fittings
4,000 psi gauge
(280 bar gauge)
Unit equipped with fittings from factory.
1,000 psi gauge
(70 bar gauge)
Unit equipped with fittings from factory.
300 psi gauge
(21 bar gauge)
Requires a #4 o-ring Boss Fitting with
Diagnostic Nipple.
TEST
LOCATION
Hydraulic Pump Flow Test
To check flow readings, a flow meter capable of measuring 60 gpm (3,8 liter/sec) and a load valve capable of 6,000
psi (413,4 bar) will be required (not included with Hydraulic Diagnostic Test Kit).
2,000 psi (137,8 bar) load @ Engine Speed of 2,500 ±25 rpm — Flow rate should be 34-40 GPM (2,1-2,5 liter/sec).
TEST
LOCATION
Valve
Port
ADJUST.
LOCATION
COMPONENT
DESCRIPTION
PRESSURE
READINGS
PRESSURE TEST PROCEDURES
VG Unloader Valve
Main System Relief
3,000 ±100 psi
(207 ±7 bar)
With engine at high idle, use the boom control lever to fully retract the boom.
Hold over relief and check pressure. If pressure is incorrect, adjust or replace
cartridge.
Auxiliary
Hydraulics
3,000 ±100 psi
(207 ±7 bar)
With engine at high idle, move auxiliary control lever left or right. Hold auxiliary
control lever over relief and check pressure. If pressure is incorrect, check
unloader pressure per
. If is ok, check port reliefs on the aux section of
main control valve (consult factory).
VG
N/A
Attachment Tilt
Relief/
FORWARD
or REARWARD
3,000 ±100 psi
(207 ±7 bar)
CONSULT FACTORY
VG Unloader Valve
See
Standby Pressure
250-300 psi
(17-21 bar)
Note: DO NOT touch any functions while the pressure gauge is connected.
You will damage the pressure gauge.
With engine at idle and no functions operated, check standby pressure. If
pressure is incorrect, adjust or replace the differential pressure sense
cartridge on the unloader valve.
LSG N/A Unloader Valve
Load Sense
0-3,000 psi
(0-207 bar)
With engine at idle, load sense is 0 psi.
With engine at FULL throttle, use the boom control lever to fully retract the
boom. Hold over relief. Pressure should be 2,750-3,000 psi (190-207 bar).
PSG
Secondary
Function
Manifold
Steering Relief
2,500 ±100 psi
(172 ±7 bar)
With engine at FULL throttle, turn the steering wheel all the way in one
direction and hold while checking pressure. If pressure is incorrect, adjust or
replace the pressure-reducing cartridge.
PBG N/A
Secondary
Function
Manifold
See
Park Brake
400 psi (28 bar)
minimum
500-600 psi
(34-41 bar)
maximum
With engine at idle, park brake released and no functions operated, pressure
should be 400 psi (28 bar) minimum.
With engine at idle, park brake released and steering held over relief,
pressure should be 500-600 psi (34-41 bar) maximum.
After releasing the steering wheel, the pressure MUST NOT drop more than
50 psi in one minute. If pressure drop is incorrect, refer to brake system
information in the service manual.
If pressure is incorrect, adjust per test
.
PPG
Secondary
Function
Manifold
See
500-600 psi
(34-41 bar)
With engine at idle, park brake released and steering held over relief while
checking pressure. If pressure is incorrect, adjust or replace the pressure
reducing valve in the secondary function manifold.
N/A
Brake Valve
(Manual Brake
Pressure)
See
400 psi
(28 bar)
minimum
With engine OFF, pump brake pedal twice. DO NOT overstroke the brake
pedal. If pressure is incorrect, check for external leaks. If no leaks are found,
refer to brake system information in the service manual.
N/A
Brake Valve
(Service Brake
Pressure)
See
550 psi
(38 bar)
minimum
With engine at idle, depress and hold brake pedal. DO NOT turn steering
wheel. DO NOT overstroke the brake pedal. Check pressure. If pressure is
incorrect, refer to brake system information in the service manual.
G1
Stabilizer
Cylinder
See
75-150 psi
(5,2-10,3 bar)
With the engine at idle, check the pressure on the cylinder.
2 5 4
6 7 8 3
9
CAUTION:
GAUGE DAMAGE may occur. Malfunctioning hydraulic system circuits
may have excessive pressure and can cause hydraulic pressure spikes. Test circuit with
the highest reading pressure gauge first. If this gauge cannot record an accurate
pressure reading, use the next lower pressure gauge.
1
2 2
2 2
2 2
2
3 3
4
5 5
6
7
7 7
8
8
9 9