Allied 300, Technical Manual, Page: 36 / 66

Allied Construction Products, LLC Technical Manual Ho-Pac 300, 300B & 500, 500B
25
9.1 Testing the Hydraulic Circuit
The hydraulic system of the host machine is
utilized to supply power to the Ho-Pac.
It’s
important to evaluate the hydraulic circuit of
the machine with a flow meter.
Before starting a flow test, make sure the
circuit to be tested has a relief valve. After
the tests are completed, compare the
results with the specifications in Section 5.1.
Never attempt to operate the Ho-Pac until
the results recorded below are in
accordance with the specifications listed for
your model.
In order to get an accurate assessment of
the hydraulic circuit, conduct the test over a
range of conditions, including temperatures,
mode, engine speed and load. Use the
space provided to record your results.
Mode
Engine
RPM Flow
[GPM]
Load
Pressure
[PSI] Oil
Temp
[ºF] Relief
Pressure
[Crack] Relief
Pressure
[Dynamic] Return
Pressure
[PSI]
0
1000
1500
1800
2000
2200
2400
2600
2800
3000
3200
3400
Mode
– Set the mode selector to Breaker
position (if equipped).
Engine RPM
– Set to normal operating
speed
Flow [GPM]
– Record flow meter readings
according to the given load increments
Load Pressure [PSI]
– Increase load on
hydraulic circuit by slowly closing restrictor
valve on flow meter.
Oil Temperature
– Testing must be done
while the hydraulic oil temperature is at
normal operating temperature. [130-170 F]
Relief Pressure [Crack]
– Slowly close
restrictor valve until pressure gage indicates
relief valve has cracked open.
Relief Pressure [Dynamic]
– Adjust
restrictor valve until pressure gage indicates
relief valve has reached full open and all oil
is bypassed through relief valve.
Return Pressure [PSI]
– Record the
pressure measured in the return line
pressure.
Procedures described are for typical carriers
and flow meters. Procedures may vary and
you should always consult the manual
provided by the manufacturer of the flow
meter for specific installation and operating
details.
Follow all safety precautions.