Service Manual User Manual

Hydraulic System
9-77
Boom Extend/Retract Section
1. Install the poppet (24, Fig. 9– 54), spring (25) and
shuttle (21) into the boom extend/retract section
assembly (8).
2. Install a new O-ring (20) into the boom extend/retract
section assembly (8).
3. Carefully attach the boom extend/retract section
assembly (8) to the boom hoist/lower section
assembly (9) and outlet section assembly (7).
Assembling the Relief Valve Assemblies
Relief valve assembly (27, Fig. 9– 54) is oriented toward
the rear of the vehicle and is preset at 3750± 50 psi (258
± 3,5 bar). Relief valve assembly (28) is oriented toward
the front of the vehicle and is preset at 3200± 50 psi (220
± 3,5 bar).
For each relief valve assembly (27 and 28, Fig. 9– 54):
1. Install a new O-ring (29, Fig. 9– 54) and the spring
(34) into the housing (51).
2. Install a new back-up ring (32), new O-ring (31),
another new back-up ring (32), spring (33), and the
piston (52) into the housing (51).
3. Install the relief valve poppet (53), new O-ring (30),
and new back-up ring (35).
4. Install a new back-up ring (35), new O-ring (30), and
the relief valve poppet (53) into the housing (51), then
install the check valve poppet (54) into the housing
(51).
5. Place the pilot poppet (50) and spring (36) into the
housing (51), then add a new O-ring (29) and secure
with the plug (49).
6. Install jam nut (48), back-up rings (47), poppet (46),
and plug (45).
7. Use a wrench on the housing (51) to install the relief
valve assembly (27 and/or 28) into the section
assembly.
Boom Hoist/Lower Section
1. Install the anti-void assembly (26, Fig. 9– 54) into the
boom hoist/lower section assembly (9).
2. Install the poppet (24), spring (25) and shuttle (21).
3. Install a new O-ring (20), then carefully attach the
boom hoist/lower section assembly (9) to the outlet
section assembly (7).
Extend/retract and hoist/lower outlet section assembly
Install the shut-off plug assembly orifice (6, Fig. 9– 54)
into the outlet section assembly (7).
g. Main Control Valve Installation
1. Place the main control valve into position on the valve
plate assembly.
2. Align gaskets, bolt holes, etc. with component mount
holes. Secure the main control valve with the
necessary fasteners. Torque fasteners to
specification. Refer to the torque specification chart
in
Section 2 General Information, Specifications and
Maintenance Instructions
.
3. Prime the main control valve by filling the inlet
openings with fresh, filtered hydraulic oil before
attaching the hoses.
4. Use new O-rings as required. Reattach and secure
all hoses, clamps, etc.
5. Check the routing of all hoses, wiring and tubing for
sharp bends or interference with any rotating
members, and install tie wraps and/or protective
conduit as required. Tighten all tube and hose
clamps.
6. Start the engine and run at approximately one-third
to one-half throttle for about one minute without
moving the vehicle or operating any hydraulic
functions.
7. Inspect for leaks and check the level of the hydraulic
fluid in the reservoir. Shut the engine OFF.
Note: Check for leaks and repair as required before con-
tinuing. Add hydraulic fluid to the reservoir as needed.
8. Conduct a pressure check of the hydraulic system in
its entirety. Adjust pressure(s) as required.
9. Wipe up any hydraulic fluid spillage in, on, near and
around the vehicle, work area and tools.
WARNING: Avoid prolonged engine operation
in closed areas with inadequate ventilation.
Failure to properly ventilate exhaust fumes can
result in death or severe personal injury.
Model 3606 • Origin 10/99