Groundsmaster 4300--DHydraulic System Page 4 -- 50
Lift Relief Valve (PRV) Pressure Test
Figure 51
GEAR
PUMP
LIFT
CONTROL
MANIFOLD
TO STEERING
CONTROL VALVE
PRESSURE
GAUGE
INTERNAL
CASE
DRAIN
PUMP(P5)
TO DECK CONTROL MANIFOLD
(REAR CUTTING UNITS)
(FRONT CUTTING UNITS)
TO DECK CONTROL MANIFOLD
FROM MOW CONTROL
MANIFOLD
The lift relief valve (PRV) pressure test should be per-
formed to make sure that the lift c ircuit relief pressure is
correct.
Procedure for Lift Relief Valve (PRV) Pressure
Test
1. Make sure hydraulic oil is at normal operating tem-
perature by operating the machine under load for
approximately ten (10) minutes.
2. Park machine on a level surface with the cutting
decks lowered and PTO switch off. Make sure engine is
off. Apply the parking brake.
3. Read Precautions For Hydraulic Testing in this sec-
tion.
CAUTION
Before opening hydraulic system, operateall 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.
4. Gain access to hydraulic lift control manifold by re-
moving the operator floor plate. The lift control manifold
is attached to a frame bracket under the floor plate (Fig.
52).
