Service And Repairs 4 - Toro 04384 Service Manual

Procedure for Implement Relief Valve Pressure Test
1. Make sure hydraulic oil is at normal operating tem-
perature by operating the machine for approximately ten
(10) minutes.
2. Park machine on a level surface with the cutting units
lowered. Make sure engine is off. Make sure the hydrau-
lic tank is full.
CAUTION
Before continuing further, read and become fa-
miliar with Precautions for Hydraulic Testing.
3. Measure and record charge relief valve pressure
(see Charge Relief Valve Pressure Test in this section).
4. Thoroughly clean junction of hydraulic hose and the
hydraulic fitting in the rear gear pump section (Fig. 22).
This hose leads to port P in the steering valve.
5. Disconnect the hose from the fitting in the rear gear
pump section.
6. Install tester with pressure gauge and flow meter in
series with the gear pump fitting and the disconnected
hose (same connections as Gear Pump (Rear Section)
Flow Test). Make sure flow control valve on the tester
is fully open.
7. Start and run engine at full speed (2750 + 50 RPM).
CAUTION
When performing test, do not allow system pres-
sure to exceed 1400 PSI (83 bar).
8. Watch the pressure gauge on the tester and move
the joystick to the raise position. Momentarily hold the
joystick with the cutting units fully raised causing the im-
plement relief valve to open. Record pressure at which
the relief valve opens.
9. Release joystick and shut off engine.
NOTE: The implement relief valve is in series with
charge relief valve. Charge relief pressure will affect the
implement relief pressure.
Greensmaster 3250--D
10.Implement relief valve pressure should be 1050 to
1250 PSI (73 to 86 bar) higher than the charge relief
valve (R4) pressure (e.g. if the charge relief valve pres-
sure is 100 PSI (7 bar), the implement relief valve pres-
sure should be from 1150 to 1350 PSI (80 to 93 bar)).
IMPORTANT: Hold steering wheel at full lock only
long enough to get a system pressure reading.
11. The implement relief valve is also activated by the
steering system. With tester still connected to gear
pump outlet, start engine and watch the pressure
gauge. Turn the steering wheel completely in one direc-
tion and hold. Relief valve should open just after rear
wheel gets to the full lock position. Relief pressure mea-
sured with the steering system should be similar to re-
sults in step 8 above.
12.If implement relief valve pressure is incorrect, in-
spect relief valve located in the steering valve (see
Steering Valve Service in the Service and Repairs sec-
tion of this Chapter). Clean relief valve or service steer-
ing valve as needed.
NOTE: Gear Pump (Rear Section) Flow Test and Low-
er Cutting Units Relief Valve (R2) Pressure can be mea-
sured with tester positioned as described in this check
(see Gear Pump (Rear Section) Flow Test and Lower
Cutting Units Relief Valve (R2) Pressure Test in this sec-
tion).
13.After testing is complete, remove pressure gauge
from manifold test fitting.
1
2
1. Gear pump
Page 4 - - 39
Figure 22
2. Rear section fitting
Hydraulic System