SkyTrak 6036 Service Manual - Manual (Page 218)

Section 9 Hydraulic System
9-68 Model 6036/6036T S/N 9B0500 thru 14833
2. Operate all of the hydraulic functions (boom
raise/lower and extend/retract) after the
engine has stopped to relieve any trapped
pressure.
9.6 VALVES
9.6.1 Main Control Valve Assembly
Cable Control
The main control consists of three relief valves,
two parallel working sections, and an inlet and
outlet section, Fig. 9.37. For a description of how
each component operates in a specific circuit,
refer to paragraph 9.2.
Warning
Relieve hydraulic pressure before servicing any
hydraulic component. Escaping hydraulic fluid
under pressure can penetrate the skin causing
serious injury.
Wait for the hydraulic fluid to cool before servic-
ing any hydraulic component. Hot hydraulic fluid
can cause severe burns.
Warning
3. Remove the transmission cover.
4. Remove dirt and grease from the hydraulic
lines and fittings, on main control valve (1, Fig.
9.38) and near by components.
5. Tag and disconnect the hydraulic lines from
the main control valve and cap or plug the
connectors.
6. Tag and disconnect control linkage (4) from
main control valve by removing cotter pins (2)
and retaining pins (3).
7. Remove the capscrews (5), locknuts (7), and
washers (6) securing the control valve to the
frame.
8. Remove the main control valve from the
forklift.
9. Remove any remaining dirt and grease from
the valve assembly.
b. Relief Valve Repair
Disassembly
1. Remove the relief valve from the control valve
housing.
2. Unscrew plug (12, Fig. 9.39) and remove the
relief valve cartridge from housing (2).
3. Remove and discard O-ring (1) from housing.
4. Remove acorn nut (18) and jam nut (17) from
adjustment screw (15).
5. Remove and discard O-rings (16).
a. Main Control Valve Removal
1. Engage the park lock, place the travel select
lever in neutral, and stop the engine.
INLET
PORT WORK
PORTS
OUTLET
PORT
PLUG
1
3
4
5 6
7
8
2
1. Inlet Section
2. Boom Raise/Lower Working Section
3. Boom Extend/Retract Working Section
4. Boom Extend Port Relief Valve, set at 2850 ± 50
psi
(196 ± 3,4 bar)
5. Boom Retract Port Relief Valve, set at 2850 ± 50
psi
(196 ± 3,4 bar)
6. Boom Raise Port Relief Valve, set at 2850 ± 50
psi
(196 ± 3,4 bar)
7. Main Relief Valve, set at 2700 -100/ +150 psi
(186 -6,9/ +10,3 bar)
8. Outlet Section
Fig. 9.37 Main Control Valve (Cable Control)
MA2090