Relief Valve Pressure Test - Toro Groundsmaster 3500 30807 Service Manual

Steering/Lift/Sidewinder Circuit Testing − Relief
Valve Pressure Test:
The relief valve for the steering, lift, and sidewinder cir-
cuits is integrated into the steering control valve. If both
steering and lift operations perform poorly, perform the
relief valve pressure test and gear pump (P2) flow test
(see Steering/Lift/Sidewinder Circuit − Gear Pump (P2)
Flow Test in this chapter).
NOTE: If available, using a flow meter with pressure
gauge that has at least a 5 GPM (16 LPM) capacity in-
stead of a pressure gauge (as described in this test) will
allow performing the relief valve test and the pump (P2)
flow test with the same test configuration (see Steering/
Lift/Sidewinder Circuit − Gear Pump (P2) Flow Test in
this chapter.
1. Park machine on a level surface with the cutting units
lowered and PTO switch off. Make sure engine is off and
the parking brake is engaged.
2. Read Precautions for Hydraulic Testing in this
chapter.
3. Disconnect hose connection on gear pump (P2)
leading to the steering control valve (Fig. 39).
4. Install T−connector with test gauge between the
gear pump and the disconnected hose.
5. Make sure steering wheel is positioned so the rear
wheel points directly ahead.
6. Start engine and move throttle to full speed (Diesel
engine = 3220 + 50 RPM, Gas engine = 3420 + 30
RPM).
7. Make sure hydraulic fluid is at normal operating tem-
perature by operating the machine for approximately 10
minutes.
8. Watch pressure gauge carefully while turning the
steering wheel completely in one direction and holding.
CAUTION
Do not allow pressure to exceed 1500 PSI. Hold
steering wheel at full lock only long enough to
get a system pressure reading. Holding the
steering wheel against the stop for an ex-
tended period may damage the steering con-
trol valve.
Groundsmaster 3500
RIGHT
FRONT
1. Gear pump assembly
9. System pressure should reach 940 to 1015 PSI (65
to 70 Bar) as the relief valve opens.
10.Return steering wheel to the center position and shut
off engine.
11. If specification is not met, repair or replace steering
control valve.
12.Disconnect T−connector with test gauge and recon-
nect hydraulic hose to gear pump.
Page 5 − 63
2
P2
P1
Figure 39
2. To steering control valve
Hydraulic System
1