Lake Monitors Hydraulic System Test Analyzers (Style K & T) - Manual (Page 4)

Step 1 - Basics
Before any extensive troubleshooting procedures are started, the
following several items need to be considered:
 Ensure that the suction strainer, which is located either in the line
between the reservoir and pump or inside the reservoir, is clean.
Restrictions in the pump's suction line will cause pump cavitations
and loss of high pressure and can cause excessive pump noise
and premature wear.
 Ensure that the suction line within the reservoir covered with at
least 3" of oil. Failure to maintain a flooded suction line can also
lead to the conditions stated above.
 Make an effort to obtain all product data sheets and specifications
for the equipment to be tested. Having this information at hand will
help during the diagnosis.
 Most importantly, study and apply the applicable safety guidelines
for the equipment being tested. Apply best practices and avoid
damage to equipment or personal injury.
Step 2 - Pump Output
To measure the hydraulic horsepower that is being generated by the
system's pump, the Lake System Analyzer should be plumbed directly
in-line after the system's pump outlet and relief valve. Be sure to ori-
ent the Analyzer so that its flow direction arrow corresponds
with the actual flow direction.
Open the flow control valve on the Analyzer fully CCW (counter clock-
wise), start the system and bring the oil temperature to standard oper-
ating temperature.
With the pump operating at the RPM recommended by the manufac-
turer, note the flow rate indicated on the Analyzer. Adjust the load
valve on the Analyzer CW (clockwise) until the pressure indicated on
the Analyzer is just below the relief valve setting. Note the flow rate
on the Analyzer. An indication lower than what is specified by the
pump manufacturer as an acceptable margin or a drop of more than
10% in flow rate (flow rate under pressure/flow rate at no pressure =
less than 0.9) indicates a need for pump service.
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Step 3 - Relief Valve
To test for proper operation of the system's relief valve, install the
Analyzer immediately downstream from the valve ensuring proper ori-
entation of the Analyzer. (See Illustration 2)
Open the valve on the Analyzer fully CCW (counter clockwise), start
the system and allow it to run until it reaches its normal operating
temperature as dictated by the manufacturer supplied data.
With the pump operating at the RPM recommended by the manufactur-
er, gradually close the Analyzer's load valve noting the pressure that the
flow rate drops off at. If that pressure differs from the system's design
pressure, the valve may need to be cleaned, adjusted or replaced.
This point of the procedure requires that the data from the equipment
manufacturer calls out a set point and/or an acceptable range of toler-
ance for the relief valve. Often times this information can be found on
a label or tag on the valve or pump housing.
Step 4 - Testing Hydraulic Cylinder Leakage
If the results of Steps 1 - 3 are acceptable, the problem lies down
stream from those components. One common source of poor system
performance can be faulty seals in hydraulic cylinders. To test the
cylinder's seals, make certain the cylinder is not under any mechanical
load and that the ram or piston rod is completely unobstructed.
Illustration 2
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