SkyTrak 8042 Service Manual - Manual (Page 504)

8.89 Model 8042, 10042, 10054 Legacy Rev. 10/03
Hydraulic System
g. Main Control Valve Assembly
This section covers assembly of the outlet, lift/lower,
extend/retract and mid-inlet/outlet sections of the main
control valve (1).
Note: ALWAYS replace o-rings with new o-rings
lubricated with clean hydraulic oil to help ensure a leak-
proof seal and proper vehicle performance.
Assemble the Outlet Section
1. Assemble the outlet section (6) in the reverse order
of the disassembly procedure. Refer to
“Disassemble the Outlet Section” on page 8.83.
2. Screw three nuts (2 and 3) onto three tie rods (4 and
5) and insert into the outlet section (6).
Assemble the Relief Valves (Outlet Section)
Note: There is a seal and spring kit for assembling the
relief valve.
1. Assemble the load sense (8) and main relief valves
(9) in the reverse order of the disassembly
procedure. Refer to “Disassemble the Relief Valves
(Outlet Section)” on page 8.83.
2. Install the load sense (8) and the main relief valve (9)
onto the outlet section (6).
Assemble the Lift/Lower Section
1. Assemble the lift/lower section (10) in the reverse
order of the disassembly procedure. Refer to
“Disassemble the Lift/Lower Section” on page 8.83.
2. Insert the shuttle (11), spring (12) and poppet (13)
into the section.
3. Place a new oiled o-ring (7) between the outlet
section (6) and the lift/lower section (10), and slide
the lift/lower section onto the tie rods.
Assemble Relief Valves (Extend/Retract and Lift/Lower
Sections)
There are two relief valves (19) on the extend/retract
section (14). On the lift/lower section (10), the relief valve
(19) is on the “A” side. The relief valves are preset at 3250
±50 psi (224 ±3,5 bar).
Note: There is a seal and spring kit for assembling the
relief valves.
For each relief valve (19):
1. Assemble the relief valve (19) in the reverse order of
the disassembly procedure. Refer to “Disassemble
the Relief Valve (Lift/Lower and Extend/Retract
Sections)” on page 8.85.
2. Using a wrench on the body (20), install the relief
valve (19) into the appropriate section assembly.
Assemble the Extend/Retract Section
1. Assemble the extend/retract section (14) in the
reverse order of the disassembly procedure. Refer to
“Disassemble the Extend/Retract Section” on page
8.83.
2. Insert the shuttle (15), spring (16) and poppet (17)
into the extend/retract section (14).
3. Place a new oiled o-ring (18) between the extend/
retract section (14) and the lift/lower section (10) and
slide the extend/retract section onto the tie rods.
Assemble the Mid-Inlet/Outlet Section
1. Assemble the Mid-Inlet/Outlet section (21) in the
reverse order of the disassembly procedure. Refer to
“Disassemble the Mid-Inlet/Outlet Section” on page
8.85.
2. Insert the shuttle (23) into the mid-inlet/outlet section
(21).
3. Place a new oiled o-ring (22) between the extend/
retract section (14) and the mid-inlet/outlet section
(21).
4. Torque the two tie rod nuts (2) to 43-53 lb-ft
(58-72 Nm) and the third tie rod nut (3) to 66-82 lb-ft
(89-111 Nm), holding all sections together.
5. Retrieve the attachment tilt, frame sway and auxiliary
assembly. Tighten the three tie rod nuts from this
assembly into the mid-inlet/outlet section. Refer to
“Assemble the Load Sense Outlet Section” on page
8.87, Step 2 for the torque values.
6. Ensure that the large o-ring in the frame sway
section is properly seated between the frame sway
section and the mid-inlet/outlet section. Refer to
“Assemble the Frame Sway Section” on page 8.87,
Step
4.