Toro 30881 and 30882 Lawn Mower User Manual


 
Groundsmaster 4500--D/4700--D Hydraulic SystemPage 4 -- 93
Control Manifold Cartridge Valve Service
1. Make sure the control manifold is clean before re-
moving the cartridge valve f rom the control manifold.
2. If cartridge valve is solenoid operated, remove nut
securing solenoid coil to the cartridge valve. Carefully
slidecoiloffthevalve.
IMPORTANT: Use care when handling the cartridge
valve. Slight bending or distortion of the stem tube
can cause binding and malfunction. When remov-
ing cartridge valve from manifold, make sure that
deep well socket fully engages the valve base.
3. Remove cartridge valve from manifold using a deep
socket wrench. Note correct location for O--rings, seal-
ing rings and backup rings. Remove seal kit from car-
tridge valve and discard removed seals.
4. Visually inspect the port in the manifold for damage
to the sealing surfaces, da maged threads and contami-
nation.
5. Visually inspect cartridge valve for damaged sealing
surfaces and contamination.
A. Contamination may cause valves to stick or hang
up. Contamination canbecome lodged insmall 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 goggles or other appropriate eye protection
when using compressed air for drying p arts.
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 awood 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.
7. Install the cartridge valve into the manifold:
A. Lubricate new seal kit components with clean hy-
draulic oil and install on valve. The O--rings, sealing
rings and backup rings must bearranged properlyon
the cartridge valve for proper operation and sealing.
B. Dip assembled cartridge into clean hydraulic oil.
IMPORTANT: Use care when handling the valve
cartridge. Slight bending or distortion of the
stem tube can cause binding and malfunction.
When installing cartridge valve into manifold,
make sure that deep well socket fully engages
the valve base.
C. Thread cartridge valve carefully into manifold
port by hand until the top O--ring is met. The valve
should go into manifold port easily without binding.
D. Torque cartridge valve using a deep socket
wrench to value identified in control manifold illustra-
tion.
8. If cartridge valve is solenoid operated, carefully
install solenoid coil to the cartridge valve. Secure coil to
valve with nut and torque nut to 60 in--lb (6.8 N--m).
9. If problems still exist after assembly, remove valve
and clean again or replace valve.
Hydraulic
System