Cartridge Valve Service - Toro Groundsmaster 5900 Series Service Manual

Cartridge Valve Service

Hydraulic System: Service and Repairs
1. Make sure the entire outer surface of the manifold is clean before removing
the valve.
If cartridge valve service involves any valves in the steering/deck
lift manifold, make sure that cutting decks are fully lowered before
loosening valves in the manifold. If cutting decks are not fully
lowered as valves are loosened in the steering/ deck lift manifold, a
cutting deck may drop unexpectedly.
2. If cartridge has a replaceable solenoid coil, remove nut securing solenoid coil
to the cartridge valve. Carefully slide solenoid coil off the valve.
Use care when handling the valve cartridge. Slight bending or
distortion of the stem tube can cause binding and malfunction.
3. Remove the cartridge valve:
A. Use a deep socket wrench for cartridge valves that thread directly into
the manifold blocks.
B. Use an extended hex wrench socket for flange mounted cartridge valves.
4. Record the location of seal kit components (O−rings, sealing rings, backup
rings, etc.). Remove and discard old seal kit components.
5. Visually inspect the port in the manifold for damage to the sealing surfaces,
damaged threads and contamination. Also, 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 damaged, the hydraulic system
may be overheating or there may be water in the system.
Use eye protection such as goggles when using compressed air.
6. Clean cartridge valve using clean mineral spirits. Submerge valve in clean
mineral spirits to flush out contamination. Particles as fine as talcum powder
can affect the operation of high pressure hydraulic valves. If cartridge design
allows, use a wood or plastic probe to push the internal spool in and out 20
to 30 times to flush out contamination. Be extremely careful to not damage
cartridge. Use compressed air for cleaning.
7. Reinstall the cartridge valve:
A. Lubricate new seal kit components with clean hydraulic 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.
WARNING
IMPORTANT
CAUTION
Page 5–158 Groundsmaster ® 5900 & 5910
16227SL Rev B