Toro 30821 Service Manual page 131

NOTE: The Groundsmaster 3500- D hydraulic man-
ifold uses several zero leak plugs. These plugs have a
tapered sealing surface on the plug head that is de-
signed to resist vibration induced plug loosening. The
zero leak plugs also have an O- ring as a secondary
seal. If zero leak plug removal is necessary, lightly rap
the plug head using a punch and hammer before using
an allen wrench to remove the plug: the impact will allow
plug removal with less chance of damage to the socket
head of the plug.
Cartridge Valve Service (Fig. 97)
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 coil off the valve.
IMPORTANT: Use care when handling the cartridge
valve. 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.
Groundsmaster 3500- D
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. Be ex-
tremely careful not to damage cartridge. Use com-
pressed air for cleaning.
7. Reinstall the cartridge valve into the manifold block:
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 (Fig. 97).
D. If cartridge is solenoid operated, carefully install
solenoid coil to the cartridge valve. Torque nut to val-
ue identified in manifold illustration (Fig. 97).
8. If problems still exist, remove valve and clean again
or replace valve.
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1. Manifold assembly
2. Logic valve (LC1)
Page 4 - 91
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Figure 98
3. Solenoid valve (R1)
4. Braking valve (BV)
Hydraulic System (Rev. G)
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