SkyTrak 6036 Service Manual - Manual (Page 158)

9-45 Model 6036 S/N 9B0499 and Before
Section 9. Hydraulic System
a. Main Control Valve Removal
1. Engage the park lock, place the travel select
lever in neutral, and stop the engine.
2. Operate all of the hydraulic functions (boom
raise/lower, extend/retract, grille tilt and frame
tilt) after the engine has stopped to relieve any
trapped pressure.
3. Remove the transmission cover.
4. Remove dirt and grease from the hydraulic
lines and fittings, on main control valve (6, Fig.
9.23) and nearby 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 (7) from
main control valve by removing cotter pins (1)
and retaining pins (2).
7. Remove the capscrews (5), locknuts (3), and
washer (4) 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
Operation
Fluid at supply pressure is admitted to the relief
area, Fig. 9.24, of the valve through a hole in the
piston. Initially, the pilot poppet, relief valve
poppet and check valve poppet are seated.
Wait for the hydraulic fluid to cool before servic-
ing any hydraulic component. Hot hydraulic fluid
can cause severe burns.
Warning !
Warning !
5 2 4 6
10 12 11 13 9
14
7
Relieve hydraulic pressure before servicing any
hydraulic component. Escaping hydraulic fluid
under pressure can penetrate the skin causing
serious injury.
9.3 VALVES
9.3.1 Main Control Valve Assembly
The main control consists of eight relief valves,
four directional control valves, and an inlet and
outlet section, Fig. 9.22. For a description of how
each component operates in a specific circuit refer
to paragraph 9.1.
1. Outlet Section
2. Frame Tilt Right Relief Valve
(1200 ± 50 psi or 82,7 ± 3,4 bar
setting)
3. Grille Tilt Control Valve
4. Grille Tilt Up Relief Valve
(2650 ± 50 psi
or 182,6 ± 3,4 bar setting)
5. Boom Extend Relief Valve
(2650 ± 50 psi
or 182,6 ± 3,4 bar setting)
6. Boom Hoist Control Valve
7. Main Relief Valve
(3000 ± 50 psi or 206,7 ± 3,4 bar setting)
8. Inlet Section
9. Boom Hoist Relief Valve
(2650 ± 50 psi
or 182,6 ± 3,4 bar setting)
10. Boom Extend/Retract Control Valve
11. Boom Retract Relief Valve
(2650 ± 50 psi or 182,6 ± 3,4 bar setting)
12. Grille Tilt Down Relief Valve
(2650 ± 50 psi or 182,6 ± 3,4 bar setting)
13. Frame Tilt Left Relief Valve
(1200 ± 50 psi or 82,7 ± 3,4 bar setting)
14. Frame Tilt Control Valve
Figure 9.22 Main Control Valve Components
8
3
1
MA0431