SkyTrak 8042 Service Manual - Manual (Page 152)

Hydraulic System
8-8 6036, 6042, 8042, 10042, 10054
Test
Location
Hydraulic Pump Flow Test
1 To check flow readings, a flow meter capable of measuring 60 gpm (3,8 liter/sec) and a load
valve capable of 6000 psi (413,4 bar) will be required.
2000 psi (137,8 bar) load @ Engine Speed of 2475 - 2525 rpm - Flow rate should be 28-32 GPM
(1,8-2,0 liter/sec)
Test
Location
Adjust.
Location
Component
Description
Pressure
Reading
Pressure Test Procedures
2 A Unloader
Valve
Main System
Relief
2900-3100 psi
(200-214 bar)
With engine at 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.
2 B Unloader
Valve
Lift/Lower
Relief
2900-3100 psi
(200-214 bar)
Remove the carriage if attached. With engine at full
throttle, use the boom control lever to lower boom fully.
Hold over relief and check pressure. If pressure is
incorrect, adjust or replace cartridge.
2 N/A Attachment
Tilt Relief/
FORWARD or
REARWARD
3150-3250 psi
(217-224 bar)
CONSULT FACTORY
2 D Unloader
Valve
Standby
Pressure
250-300 psi
(17-21 bar)
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.
3 N/A Unloader
Valve
Load Sense
0-3000 psi
(0-207 bar)
With engine at idle, load sense at 0 psi. With engine at
FULL throttle, use the boom control lever to fully retract the
boom. Hold over relief. Pressure should be 2750-3000 psi
(190-207 bar).
4 E Secondary
Function
Manifold
Steering Relief
2400-2600 psi
(165-179 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.
5 F Secondary
Function
Manifold
Park Brake
minimum
400 psi (28 bar)
maximum
550 psi (38 bar)
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 550 psi (38 bar) maximum.
If pressure is incorrect, adjust or replace the pressure
reducing valve in the secondary function manifold. When
adjusting the pressure reducing valve, connect gauge to
location 6. With engine at idle and steering held over relief,
adjust valve until gauge reads 500-550 psi (34-38 bar).
7 N/A Brake Valve
(Manual
Brake
Pressure)
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 Section
8.7.3, “Service Brake Valve.”
7 N/A Brake Valve
(Service
Brake
Pressure)
550 psi
(38 bar)
minimum
With engine at idle, depress and hold brake pedal. DO
NOT turn the steering wheel. DO NOT overstroke the
brake pedal. Check pressure. If pressure is incorrect, refer
to Section 8.7.3, “Service Brake Valve.”