Multi Pro 1200/1250 Hydraulic SystemPage 4 -- 15
Procedure for Steering Pump Flow and Relief
Pres-
sure
Test:
1. Make sure hydraulic oil is at normal operating tem-
peraturebyoperatingthemachineforapproximatelyten
(10) minutes.
2. Park machine on a level surface with the spray sys-
temoff.Applyparkingbrakeandmakesurerangeselec-
tor is in the neutral position.
3. Read Precautions For Hydraulic Testing.
4. Make sure that steering pump drive belt is adjusted
properly (see Operator’s Manual).
CAUTION
Before disconnecting components or perform-
inganyworkonhydraulicsystem,allpressurein
the system must be relieved by stopping the en-
gine and rotating the steering wheel in both
directions.
5. Clean hose fitting and disconnect pressure hose
from the top of the steering pump (Fig. 14).
IMPORTANT: Make sure oil flow indicator arrow on
the flow gauge is showing that the oil will flow from
the pump through the tester and into the hose.
6. Installflowtesterw ithpressuregaugesinserieswith
the pump and the disconnected hose. Make sure flow
control valve on tester is fully open.
7. To test steering pump flow:
A. Start engine andadjustenginespeed with accel-
erator pedal so pump speed is 3450 RPM (engine
speed approximately 3000 RPM). Verify pump
speed with a phototac.
B. Close flow control valve on tester until pressure
gauge reads 800 PSI (55 bar). Observe flow gauge.
TESTER READING: Flow approximately 2.7 GPM.
C. Release accelerator pedal and turn off machine.
Record test result.
8. If pump flow specification is not met, inspect for:
A. Slipping steering pump drive belt.
B. Worn, stuck or out of adjustment relief valve.
C. Pump suction line restriction.
D. Steeringpump needs to be repaired or replaced.
9. To test steering pump 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 (3275 to 3425 RPM).
IMPORTANT: Hold steering wheel at full lock
only longenough to get asystem pressure read-
ing. Holding the steering wheel against the stop
foran extended periodmay damage thesteering
control valve.
C. Watch pressuregaugecarefullywhileturningthe
steeringwheelcompletelyinonedirection(fullsteer-
ing lock) and holding.
D. System pressure should be approximately 1000
PSI (69 bar) as the relief valve lifts. Return s teering
wheel to the center position.
E. Release accelerator pedal and turn off machine.
Record test results.
10.If relief pressure is incorrect, inspect for:
A. Slipping steering pump drive belt.
B. Worn, stuck or out of adjustment relief valve in
steering pump.
11.After testing is completed, disconnect tester from
steering pump and hose. Reconnect hose to the pump.
1. Steering pump
2. Pressure hose
3. Suction hose
Figure 14
1
2
3
FRONT
Hydraulic
System
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