Toro 30821 Service Manual page 128

Braking and Logic Cartridge Valves (Fig. 92 and 93)
1. Make sure manifold is clean before removing the
cartridge.
IMPORTANT: Use care when handling the cartridge
valve. Slight bending or distortion of the stem tube
can cause binding and malfunction.
2. Remove cartridge valve using a deep socket
wrench. Note: Do not loosen locknut on top of valve.
3. Visually inspect port in the manifold for damage to
the sealing surfaces, damaged threads, or contamina-
tion.
4. Visually inspect cartridge valve for damaged sealing
surfaces or contamination.
A. Contamination may cause valves to stick or hang
up. Contaminates can become lodged in small valve
orifices or seal areas causing malfunction.
B. If sealing surfaces appear pitted or damaged, 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.
5. 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. Use
compressed air for cleaning.
IMPORTANT: Use care when handling the cartridge
valve. Slight bending or distortion of the stem tube
can cause binding and malfunction.
6. Reinstall cartridge valve:
A. Lubricate new O- rings and backup rings of seal
kit with clean hydraulic oil and install. The O- rings
and backup rings must be arranged properly on the
cartridge valve for proper operation and sealing
(Figs. 95 and 96).
B. Thread cartridge valve carefully into the applica-
ble port (Fig. 92). The valve should go in easily with-
out binding. Torque valve to 30 to 35 ft- lb (41 to 47
N- m).
C. If problems still exist, remove valve and clean
again or replace valve.
Hydraulic System (Rev. G)
1. Braking cartridge valve
2. Seal kit O- rings
1. Logic cartridge valve
2. Seal kit O- rings
Page 4 - 88
2
3
1
3
2
2
Figure 95
3. Seal kit backup rings
1
3
3
Figure 96
3. Seal kit backup rings
Groundsmaster 3500- D
3
2