Allied Construction Products, LLC www.alliedcp.com
21
TM574173_HP4000_18feb
12.0 Technical Information
12.1 Testing the Hydraulic Circuit
The performance of the Allied work tool is impaired
by a hydraulic system that is not operating correctly
or set outside the accepted specifications.
Prior to use, test and calibrate the machine's
hydraulic circuit. ‘Test and calibrate’ refers to the act
of evaluating and adjusting to meet the accepted
specifications of the Allied work tool. Refer to the
Technical Data Section of this manual for a list of
these specifications.
Tools required to complete these tests include a flow
meter and pressure gages. Tests are performed
under varied conditions, including temperature, work
mode, engine speed and load. Use the worksheet
provided below to record test results.
Work
Mode
Engine
RPM
Flow
[GPM]
Load
[PSI]
Oil Temp
[ºF]
Relief
[Crack]
Relief
[Static]
Return
[PSI]
0
1000
1500
1800
2000
2200
2400
2600
2800
3000
3200
3400
Work Mode
– Set to correct position (if equipped).
Engine RPM
– Set to normal operating speed
Flow [GPM]
– Record measured flow at each load
pressure
Load Pressure [PSI]
– Steadily increase load with
restrictor valve on the flow meter
Oil Temperature
– Oil temperature must be at
normal operating temperature while testing. Stop test
if temperature exceeds 176
q
F (80
q
C)
Relief Pressure [Crack]
– Slowly close restrictor
valve until pressure gage indicates relief valve has
cracked open.
Relief Pressure [Static]
– After cracking pressure is
reached, further adjust restrictor valve until flow gage
indicates relief valve is fully open.
Return Pressure [PSI]
– Record the pressure
measured in the return line. Measuring point for gage
must be located near the motor's outlet port.
CAUTION
Only qualified personnel, having knowledge of the
machine’s systems, proper test equipment and tools
should attempt testing and adjustments.
Testing procedures can vary depending on the
specifics of your equipment. Consult your flow meter
manual provided from the manufacturer for specific
installation and testing instructions.
Verify the circuit to be tested is equipped with a relief
valve. Before starting, be sure the restrictor valve on
flow meter is open. Include the hoses attached to the
work tool to eliminate possible faults, e.g. collapsed
hose.
