Toro Greensmaster 3120 Service Manual page 151

Rotary Valve (machines with backlap) (continued)
Greensmaster 3120
17230SL Rev C
Carefully handle the rotary valve. Slight bending or distortion
of the stem tube can cause binding and malfunction. When
removing the rotary valve from the manifold, ensure that the deep
well socket fully engages the valve base.
E. Remove the rotary valve from the manifold with a deep well socket.
5. Record location of the O-rings and the backup rings on the valve. Remove
and discard the seal kit from the rotary valve.
6. Visually inspect the manifold port and the cartridge valve:
A. Check for damaged threads on the cartridge valve and in the manifold
block.
B. If valve sealing surfaces appear pitted or damaged, the hydraulic system
may be overheating or there may be water in the system.
C. Contamination may cause valves to stick or hang up. Contamination
can become lodged in small valve orifices or seal areas causing valve
malfunction.
Use eye protection such as goggles when using compressed air.
Note: Particles as fine as talcum powder can affect the operation of high
pressure hydraulic valves.
7. Clean the rotary valve. Submerge the valve in clean mineral spirits to flush
out contamination. If the valve design allows, use a non–metallic probe to
push the internal spool in and out 20 to 30 times to flush out contamination.
Clean and dry the cartridge valve with compressed air.
8. Install the rotary valve:
A. Lubricate the new O-rings and the backup rings of the seal kit with clean
hydraulic fluid and install them on the rotary valve. The O-rings and the
backup rings must be arranged properly on the rotary valve for proper
operation and sealing.
Use care when installing the rotary valve. Slight bending or
distortion of the stem tube can cause binding and malfunction.
Make sure that deep well socket fully engages the valve base.
B. Lubricate the threads on the cartridge valve with clean hydraulic fluid.
Thread the cartridge valve carefully into the correct manifold port. The
valve should thread in easily without binding.
C. Tighten the cartridge valve using a deep well socket to the torque
specification shown.
D. Place the handle base on the flow control valve and position the alignment
mark on the base with the number 1 on manifold. Secure the base with
the two (2) set screws. Apply a light coating of grease to chamfer on top
of the base to ease the lip seal installation.
IMPORTANT
CAUTION
IMPORTANT
Page 4–105 Hydraulic System: Service and Repairs