Toro Groundsmaster 4000-D Service Manual page 121

4WD Manifold Service (Fig. 60)
1. Make sure the manifold is clean before removing the
valve.
2. If cartridge is solenoid operated, remove nut secur-
ing solenoid to the cartridge valve. Carefully slide sole-
noid off the valve.
IMPORTANT: Use care when handling the valve car-
tridge. Slight bending or distortion of the stem tube
can cause binding and malfunction.
3. Remove cartridge valve with a deep socket wrench.
Note correct location for O--rings, sealing rings and
backup rings. Remove and discard seal kit.
4. Visually inspect the port in the manifold for damage
to the sealing surfaces, damaged threads or contamina-
tion.
5. Visually inspect cartridge valve for damaged sealing
surfaces and contamination.
A. Contamination may cause valves to stick or hang
up. Contamination can become lodged in small valve
orifices or seal areas causing malfunction.
B. If valve sealing surfaces appear pitted or dam-
aged, the hydraulic system may be overheating or
there may be water in the system.
CAUTION
Use eye protection such as goggles when using
compressed air.
6. Clean cartridge valve using clean mineral spirits.
Submerge valve in clean mineral spirits to flush out con-
tamination. Particles as fine as talcum powder can affect
the operation of high pressure hydraulic valves. If car-
tridge design allows, use a wood or plastic probe to push
the internal spool in and out 20 to 30 times to flush out
contamination. Be extremely careful not to damage car-
tridge. Use compressed air for cleaning.
Groundsmaster 4000--D
7. The 4WD control manifold includes three (3) orifice
fittings (items 9 and 13). The 0.030 orifice (item 9) is
positioned in the SV port under the solenoid cartridge
valve. The 0.050 orifices (item 13) thread into the man-
ifold in ports OR1 and OR2. Before removing or instal-
ling the orifice in OR1, removal of the #6 plug in the
bottom of the manifold is necessary.
8. Reinstall the cartridge valve:
A. Lubricate new seal kit components with clean hy-
draulic oil and install on valve. The O--rings, sealing
rings and backup rings must be arranged properly on
the cartridge valve for proper operation and sealing.
IMPORTANT: Use care when handling the valve
cartridge. Slight bending or distortion of the
stem tube can cause binding and malfunction.
B. Thread cartridge valve carefully into manifold
port. The valve should go in easily without binding.
C. Torque cartridge valve using a deep socket to val-
ue identified in manifold illustration.
D. If cartridge is solenoid operated, carefully install
solenoid coil to the cartridge valve. Torque nut to val-
ue identified in manifold illustration.
9. If problems still exist, remove valve and clean again
or replace valve.
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