Operating Instructions, Form No. 102546, Back sheet 2 of 3
A TYPICAL TESTING PROCEDURE:
The following example will illustrate how this hydraulic tester is used to locate a hydraulic system malfunction. The
hydraulic system illustrated below consists of a reservoir, a pump, a relief valve, a directional control valve and a
double-acting cylinder. The problem: the cylinder's piston moves out at almost normal speed under no load, but
gradually slows down as the load increases. The trouble can lie anywhere in the system. First, all hoses and
connections should be checked for leakage, and if the trouble does not lie there, the hydraulic tester should be used
to check each of the system's components for efficiency.
TESTING THE PUMP . . . Step 1. See Diagram 1. Connect line (A) between hydraulic tester's outlet port and
system's reservoir. This connection can be maintained until all testing is completed. Step 2. Disconnect line (B)
between pump and relief valve. Connect line (C) between discharge port of pump and hydraulic tester's inlet port.
Next,
open pressure control valve of hydraulic tester by turning knob counterclockwise.
Turn pulsation
dampener knob counterclockwise several turns. Start pump. Set engine RPM for rated speed of pump (Equipment
manufacturer's specified RPM level for a given rate of flow). If the action of the gauges is erratic and severe pulsation
occurs, even after the dampener knob has been adjusted, cavitation of the pump may be indicated. . . Pressure
readings are made from tester's pressure gauge. When normal operating temperature is reached, open pressure
control valve by turning knob counterclockwise and refer to flow-meter gauge, recording volume at low pressure.
Increase pressure by turning knob clockwise, and record volume at increments up to maximum pressure. Open
pressure control valve and shut off pump. Now, check results against manufacturer's recommended ratings. If results
are low, the trouble is in the pump, suction line or filter. If results check, the trouble is beyond the pump, and we must
next check the relief valve. Disconnect line (C) between hydraulic tester's inlet port and discharge port of pump.
Reconnect line (B) between pump and relief valve.
TESTING THE RELIEF VALVE . . . See Diagram 2. Disconnect line (D) between relief valve and directional valve,
and connect line (E) between relief valve and tester's inlet port.
Open pressure control valve.
Turn dampener
temperature has been reached, record volume and pressure at various increments to maximum pressure. The
pressure at which the flow falls off to 0 is the relief pressure. If this pressure is below maximum operating pressure,
the relief valve should be adjusted. Up to relief pressure, flow should be the same as that of the pump. If it is not, this
is an indication that the relief valve is leaking and should be repaired. If the trouble does not lie in the relief valve, the
directional valve must be tested next. Disconnect line (E) between relief valve and hydraulic tester's inlet port.
Reconnect line (D) between relief valve and directional valve.
DIAGRAM 1 -- TESTING HYDRAULIC PUMP
DIAGRAM 2 -- TESTING RELIEF VALVE
