Service Manual

Rev. A
Groundsmaster 7200/7210 Hydraulic SystemPage 4 - 91
Deck Lift Manifold Service (Figure 104)
CAUTION
Before opening hydraulic system, operate all hy-
draulic controls to relieve system pressure and
avoid injury from pressurized hydraulic oil. See
Relieving Hydraulic System Pressure in the Gen-
eral Information section of this chapter.
WARNING
If lift control manifold is attached to machine,
make sure that cutting deck is fully lowered and
supported before loosening hydraulic lines, car-
tridge valves or plugs from lift manifold. If deck is
raised as manifold components are loosened,
deck may drop unexpectedly.
IMPORTANT: The two (2) solenoid valves in the
deck lift manifold are different. Label the valves be-
fore removal so the valves can be correctly installed
into the manifold.
1. Make sure the lift control manifold is clean before re-
moving the cartridge valve from the manifold.
2. Remove nut securing solenoid coil to the cartridge
valve. Carefully slide coil off the valve.
IMPORTANT: Use care when handling the cartridge
valve. Slight bending or distortion of the stem tube
can cause b inding 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, damaged 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 can become lodged in small valve
orifices or seal areas causing malfunction.
B. Ifvalvesealingsurfaces appear pitted or dam-
aged, 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.
CAUTION
Abrupt movement of internal spools can cause
stored fluid to be released suddenly.
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 a wood 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 be arranged properly on
the cartridge valve for proper operation and sealing.
B. Dip assembled cartridge into clean hydraulic oil.
IMPORTANT: Use care when handling the valve
cartridge. Sligh t bending or distortion of the
stem tube can cause binding and malfunction.
When installing cartridge valve in to 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.Torquecartridgevalveusingadeepsocket
wrench to value identified in Figure 104.
8. 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 manifold assembly, r e-
move cartridge valve and clean again o r replace valve.
Hydraulic
System