Toro Greensmaster 3120 Service Manual page 154

Spool Valve (machines with backlap) (continued)
Hydraulic System: Service and Repairs
5. Visually inspect the manifold port and the spool valve:
A. If valve sealing surfaces appear pitted or damaged, the hydraulic system
may be overheating or there may be water in the system.
B. Contamination may cause the valve to stick or hang up. Contamination
can become lodged in small valve orifices or seal areas causing valve
malfunction.
6. Install the spool valve:
A. Lubricate the new O-rings and the backup rings of the seal kit with clean
hydraulic fluid and install them on the spool valve. The O-rings and the
backup rings must be arranged properly on the spool valve for proper
operation and sealing.
B. Carefully push the spool down into the manifold port until the lower
O-ring and back-up ring groove is exposed on the bottom of the manifold.
Install the lower O-ring and back-up ring to the spool. Apply a light
coating of grease to the O-ring.
C. Install the lower retaining ring to the spool.
D. Carefully raise the spool until the upper retaining ring groove on the spool
is exposed on top of the manifold. Install the upper retaining ring.
E. If the handle was removed from the spool, position the spool so the
handle location is between the stop pins in the manifold. Apply a high
strength retaining compound (Loctite® #603 or equivalent) to the threads
on the handle and install the handle into the spool.
F. Place the ball and the dowel pin in the backlap switch manifold port.
Install a new O-ring onto the backlap switch. Thread the backlap switch
into the port and tighten to 27 N∙m (20 ft-lb).
Page 4–108 Greensmaster 3120
17230SL Rev C