Inspect
Inspect the tilt control valve section mating surfa-
ces and any open bores for damage. If damage is
found, replace the tilt control valve section. If the
spool has been removed, inspect the spool and the
bore for the spool for damage. If damage to either
the spool or the bore is found, replace the tilt con-
trol valve section.
NOTE:
If the tilt control valve section is not to be
reassembled immediately, coat surfaces with clean
hydraulic oil to prevent the possibility of rust.
Cover the tilt control valve section with a clean,
dry, lint-free cloth to prevent the possibility of con-
taminants entering the tilt control valve section.
Assemble
NOTE:
Coat all backup rings and O-rings with a
light coat of clean hydraulic oil to make installation
easier.
1.
Install the piston, spring, and socket head cap-
screw in the spool. See Figure 8.
2.
Install the spool, washer, spring, and plug, with
new O-ring, into the bore of the tilt control
valve section. Tighten the plug to 14
±1 N•m (120 ±12 lbf in).
3.
Install the washer, spring, and plug, with new
O-ring, into the tilt control valve section.
Tighten the plug to 14 ±1 N•m (120 ±12 lbf in).
4.
Install two poppets, two springs, and two plugs,
with new O-rings installed, into the tilt control
valve section. Tighten the plugs to 81
±8 N•m (60 ±6 lbf ft). See Figure 8.
5.
Install the new O-ring, backup ring, two O-
rings, and backup ring on each PPRV. Install
two PPRVs and four capscrews into the tilt con-
trol valve section. Tighten the capscrews to 3
±0.3 N•m (24 ±2 lbf in).
Install
1.
Install new O-rings on the side of lift/lower con-
trol valve section.
2.
Install the tilt control valve section on the lift/
lower control valve section.
3.
Install the auxiliary I and II (if equipped) con-
trol valve sections. See Auxiliary Control Valve
Section, Install.
4.
Install the outlet control valve section. See Out-
let Control Valve Section, Install.
5.
Install the four nuts on the tie rods of the outlet
control valve section. Tighten the three
13 mm (½ in.) nuts to 24 ±2 N•m (212
±18 lbf in) and the 15 mm (9/16 in.) nut to 45
±4 N•m (33 ±3 lbf ft). See Figure 6.
Lift/Lower Control Valve Section
Remove
1.
Remove the outlet control valve. See Outlet
Control Valve Section, Remove.
2.
Remove the auxiliary control valve section(s).
See Auxiliary Control Valve Section, Remove.
3.
Remove the tilt control valve section. See Tilt
Control Valve Section, Remove.
4.
Remove lift/lower control valve section from
transition control valve section.
5.
Remove and discard O-rings from side of transi-
tion control valve section.
Disassemble
NOTE:
Disassemble the lift/lower control valve sec-
tion only as needed to accomplish the repairs re-
quired.
1.
Remove four socket head capscrews and two
proportional pressure-reducing valves (PPRV)
from top and bottom of lift/lower control valve
section. See Figure 9. Remove and discard the
O-rings and backup rings from each PPRV.
2.
Remove the socket head plug from bottom of
lift/lower control valve section. Remove and dis-
card O-ring from plug. See Figure 9.
3.
Remove the spring, spool, piston, backup ring,
and washer from the bottom of lift/lower control
valve section. See Figure 9.
Main Control Valve Repair
2000 SRM 1899
12