Allied Construction Products, LLC www.alliedcp.com
TM576981_HP700B_18feb
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12.0 Technical Information – [cont'd]
12.2 Oil Pressure Check
IMPORTANT
The Ho-Pac is designed to provide optimum
performance with reliable service at specific oil flow
and pressure. Inattention to correct machine set up
may result in equipment damage, diminished service
life and poor efficiency.
Measure Oil Pressure Whenever the Following
Conditions Occur
x
When first installed on a carrier
x
Anytime repairs or modifications are made to the
machine’s hydraulic circuit.
x
The machine operates other hydraulic work tools.
x
Anytime the Ho-Pac is removed from one
machine and attached to a different machine.
x
Check the pressure every 250 operating hours is
recommended.
12.3 How to Measure the Oil Pressure
CAUTION
Only qualified personnel, having knowledge of the
machine’s systems, proper test equipment and tools
should attempt testing and adjustments.
WARNING
Prevent accidental start. Engage
interlock, shut off engine and apply
parking brake. Follow all safety and
operating instructions provided by the
carrier manufacturer.
Certain tests, such as measuring the oil pressure,
can only be done while the Ho-Pac is operating.
x
Lower the Ho-Pac to the ground and stop the
carrier engine.
x
Relieve hydraulic pressure in attachment circuit.
x
Connect a pressure gauge [0-5000 PSI] to the
supply hose at the [IN] side of the Ho-Pac.
x
Use the form provided in Section 12.1 to record
your results.
x
Start the carrier. Use the boom and arm controls
to extend the Ho-Pac away from the carrier.
Position the tamper plate against the ground.
x
Adjust the engine's rpm to the normal operating
speed and set operating mode to "work tool".
x
The test can begin when the normal operating
temperature is reached.
x
Start the Ho-Pac and record the pressure
reading. It's normal for the pressure reading to
increase and decrease as the carrier applies
varying amounts of down pressure.
x
Compare your results with the values listed in the
General Specifications Table.
x
When finished with the pressure-measuring test,
lower the Ho-Pac safely on the ground and stop
the engine. Relieve hydraulic pressure in
attachment circuit. Remove test gauge.
12.4 Definition of Hydraulic Terms
For the purposes of this manual, the following terms
are defined as:
Range
– A range is represented by two values 'V1 –
V2' and generally means the lowest-to-highest limit of
a device that will allow it to adequately respond. The
term “minimum flow” describes the least amount
required that permits continuous operation that is
both satisfactory and efficient.
Hydraulic Flow
– Is a measure of the volume of oil
(values given in GPM / LPM) necessary for the safe
and efficient operation of the Allied work tool.
Efficient performance is directly related to speed of
the motor. The speed at which the motor is spun
must be kept inside a narrow flow range. Under-
speeding the motor with too little flow will result in
poor performance. Excessive flow (above the
accepted flow rate) does not improve compactor
performance. Too much flow not only results in
overheating the oil, but also causes the motor to
over-speed which can add significantly higher loads
that contribute to early bearing failure.
IMPORTANT
Never use a relief valve as a means to reduce the
hydraulic oil flow to the Ho-Pac. Oil by-passed
over the relief valve will cause significant heat
generation.