Toro Multi Pro 1750 Service Manual page 70

Testing Steering Pump Flow and Relief Pressure
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 spray sys-
tem off. Apply parking brake and make sure range selec-
tor is in the neutral position. Tilt operator seat forward.
3. Read Precautions For Hydraulic Testing in this chap-
ter.
CAUTION
Before disconnecting components or perform-
ing any work on hydraulic system, all pressure in
the system must be relieved (see Relieving Hy-
draulic System Pressure in this chapter).
4. Clean hose fitting and disconnect pressure hose
from the top of the hydraulics enable valve (Fig. 16).
IMPORTANT: Make sure oil flow indicator arrow on
the flow gauge is showing that the oil will flow from
the hydraulics enable valve through the tester and
into the machine hydraulic system.
5. Install flow tester with pressure gauges in series with
the enable valve and the disconnected hose. Make sure
flow control valve on tester is fully open.
6. To test steering pump flow:
A. Start engine and set accelerator pedal to full
speed.
B. Verify with a phototach that the engine/pump
speed is approximately 3400 RPM. Adjust engine
speed if necessary (see Adjust Engine Speed in
Chapter 3 − Kohler Gasoline Engine in this manual).
C. Close flow control valve on tester until pressure
gauge reads 800 PSI (55 bar). Observe flow gauge.
TESTER READING: Flow approximately 3.5 GPM.
D. Release accelerator pedal and turn off machine.
Record test result.
7. If pump flow specification is not met:
A. Check pump suction line for restrictions.
B. Test hydraulic pump relief valve (procedure fol-
lows).
C. Hydraulic pump needs to be repaired or replaced.
Hydraulic System
3
2
FRONT
1. Hydraulic pump
2. Hydraulics enable valve
8. To test hydraulic pump relief pressure:
A. Make sure flow control valve on tester is fully
open.
B. Start engine and set accelerator pedal to full
speed.
C. Verify with a phototach that the engine/pump
speed is approximately 3400 RPM. Adjust engine
speed if necessary (see Adjust Engine Speed in
Chapter 3 − Kohler Gasoline Engine in this manual).
IMPORTANT: Hold steering wheel at full lock only
long enough to get a system pressure reading.
Holding the steering wheel against the stop for
an extended period may damage the steering
control valve.
D. Watch pressure gauge carefully while turning the
steering wheel completely in one direction (full steer-
ing lock) and holding.
E. System pressure should be approximately 1000
PSI (69 bar) as the relief valve lifts. Return steering
wheel to the center position.
F. Release accelerator pedal and turn off machine.
Record test results.
9. If relief pressure is incorrect, repair or replace relief
valve in hydraulic pump.
10.After testing is completed, disconnect tester from
steering pump and hose. Reconnect hose to the pump.
Check and adjust hydraulic oil level.
Page 4 − 22
1
Figure 16
3. Pressure hose
Multi Pro 1750