JLG Skytrak 6036 Service Manual page 161

Section 9. Hydraulic System
5. Insert pilot poppet (13) and spring (14) into the
plug.
6. Install adjustment screw (15) into the plug.
7. Lubricate and install new O-rings (16 and 18)
on nuts (17 and 19). Stretch O-rings, do not
roll them to fit.
8. Install jam nut (17) and acorn nut (19) on the
adjustment screw. Torque nuts on relief valve
to 10 ± 1.5 lb-ft (13,5 ± 2 N m).
9. Install the relief valve cartridge in the housing.
The cartridge is a honed fit and may require
gentle tapping to install.
IMPORTANT: Care must be taken to avoid
damaging the valve's internal lands.
10. Lubricate and install new O-ring (9) on hous-
ing (8). Stretch O-ring, do not roll it to fit.
11. Install assembled relief valve in the control
valve housing. Torque all relief valves except
main relief valve to 40 ± 4 lb-ft (55 ± 5,5 N m).
Torque main relief valve to 60 to 80 lb-ft (82 to
109 N m).
12. Adjust relief valve pressure as instructed in
paragraph 9.1.
1. Special Nuts (4)
2. Inlet Section
3. O-rings (5)
4. Boom Hoist Section
5. Boom Extend Section
6. Grille Tilt Section
7. Frame Tilt Section
8. Outlet Section
9. Tie Rods (2)
10. Tie Rod
11. Spring
12. Check Valve Poppet
13. Special Nuts (2)
2
1
Model 6036 S/N 9B0499 and Before
c. Repair of Main Control Valve
To replace seals between the sections of the main
control valve:
1. Remove nuts (1 and 13, Fig. 9.26) at outlet
2. Remove outlet section carefully to avoid losing
3. Remove O-ring (3) and discard.
4. Remove spring (11) and check valve poppet
5. Repeat steps 2, 3 and 4 for the remaining
6. Remove nuts (1 and 13) and tie rods (9 and
Clean all metal parts in an approved solvent such
as trichlorethylene and blow dry.
1. Thread nuts (1, Fig. 9.26) onto ends of tie rods
3
Fig. 9.26 Main Control Valve Sections
Disassembly
section (8).
spring (11).
(12) from frame tilt section (7).
valve sections (6, 5, and 4).
10) at inlet section (2).
Cleaning and Drying
Assembly
(9 and 10) until nuts are flush with the ends of
the tie rods.
9
6
5
4
1
13
10
8
11
12
7
MA0671
9-48