Toro 07390 Workman HDX-Auto, Руководство по обслуживанию, Страница: 205 / 280

Workman HDX Auto Page 7 − 21 Hydraulic System
Procedure for Gear Pump Flow and System Relief
Pressure Test
1. Make sure hydraulic oil is at normal operating tem-
perature by operating the vehicle for approximately ten
(10) minutes.
2. Park vehicle on a level surface, raise and support
cargo bed (if installed), shut engine off and engage the
parking brake. After turning engine off, operate all hy-
draulic controls to relieve hydraulic system pressure.
CAUTION
Prevent personal injury and/or damage to equip-
ment. Read all WARNINGS, CAUTIONS and Pre-
cautions for Hydraulic Testing at the beginning of
this section.
IMPORTANT: Make sure that the oil flow indicator
arrow on the flow meter is showing that the oil will
flow from the pump, through the tester and into the
hydraulic hose.
3. With the engine off, clean hose fitting and disconnect
the pressure hose from the gear pump (Fig. 18). Install
tester with pressure gauges and flow meter in series be-
tween the gear pump and the disconnected hose. Make
sure the tester flow control valve is open.
4. Make sure the hydraulic reservoir is full after con-
necting the tester.
CAUTION
The engine must be running to perform hydraulic
tests. To guard against possible personal injury,
engage parking brake and keep clothing, hands,
feet, face and other parts of the body away from
fan and other moving parts.
5. After installing tester, start engine and run at low idle
speed. Check for hydraulic leakage and correct before
proceeding with test.
IMPORTANT: In this test, the flow tester is posi-
tioned before the relief valve. Pump damage can oc-
cur if the oil flow is fully restricted.
6. Fully depress and hold accelerator pedal. Check that
engine speed is 3600 RPM. Verify engine speed with a
phototac.
7. While watching tester pressure gauges, slowly close
flow control valve on the tester until 1500 PSI (103 bar)
is obtained on gauge. Verify that engine speed contin-
ues to be correct (3600 RPM). Record flow meter read-
ing.
GAUGE READING TO BE: For a pump in good con-
dition, flow should be approximately 4.5 GPM (17.0
LPM) at 1500 PSI (103.4 bar).
8. Open tester flow control valve, release accelerator
pedal and stop engine.
9. If measured flow is less than 3.8 GPM or a pressure
of 1500 PSI (103 bar) cannot be obtained, inspect for:
A. Pump suction line restriction.
B. Gear pump needs to be repaired or replaced.
10.To test system relief pressure:
A. Make sure flow control valve on tester is fully
open.
B. Start engine and depress accelerator pedal so
engine is running at high idle (3600 RPM).
IMPORTANT: Hold steering wheel at full lock
only long enough to get a system pressure read-
ing. Holding the steering wheel against the stop
for an extended period can damage the steering
control valve.
C. Watch pressure gauge carefully while turning the
steering wheel completely in one direction (full steer-
ing lock) and holding momentarily.
D. System pressure should be approximately 1800
PSI (124 bar) as the relief valve lifts. Return steering
wheel to the center position.
E. Release accelerator pedal to allow engine to re-
turn to low idle and turn off vehicle. Record test re-
sults.
11. If relief pressure is incorrect, inspect for a worn or
stuck relief valve in steering control valve (see Steering
Control Valve Service in the Service and Repairs section
of this chapter).
12.After testing is completed, remove tester and rein-
stall disconnected hose.
Hydraulic
System