Operating Instructions
Form No. 102546
TESTING THE DIRECTIONAL VALVE . . . See Diagram 3. Disconnect line (F) between cylinder port (G) of
directional valve and pressure end (H) of cylinder. Connect line (J) between cylinder port (G) of directional valve and
hydraulic tester's inlet port.
Open pressure control valve.
Turn dampener knob counterclockwise several turns.
Start pump, set engine RPM for rated speed of pump. After operating temperature has been reached, shift directional
valve to direct oil from cylinder port (G) of directional valve to hydraulic tester's inlet port. Record pressure and
volume at various increments as was done in testing the pump and relief valve. If full volume and pressure cannot be
obtained, the directional valve is the cause of trouble, and must be repaired or replaced. If full rated volume at full
pressure is recorded, however, the trouble is in the cylinder.
TESTING WITH A "T" CONNECTION...
The above diagram illustrates a method of testing overall-circuit performance. Connect line (K) from hydraulic tester's
inlet port to a "T" connection in the circuit, as shown.
Open tester's pressure control valve.
Turn dampener knob
counterclockwise several turns. Start pump, set engine RPM for rated speed of pump. After operating temperature
has been reached, shift directional control valve to direct oil through relief valve (M), to cylinder port (L). Close
tester's pressure control valve partially to allow cylinder to extend and "dead-end."* Oil will flow to reservoir either
through the hydraulic tester or through leaks in components of the circuit. Read flow at no load. Increase load on
circuit by slowly closing the tester's pressure control valve and read flow at a pressure slightly below the relief valve
setting. The difference in readings indicates oil lost because of leaks somewhere in the circuit. Continue to increase
load until the indicated flow drops drastically, and take pressure reading. . . this reading indicates setting of relief valve
(M). To obtain setting of relief valve (N), shift directional control valve to direct oil to cylinder port (O) and repeat
procedure described above. To isolate the defective component, tests as described in Diagrams 1, 2 and 3 should be
used.
*If design characteristics of the cylinder make a "dead-end" inadvisable, simply plug the end of the line leading to the
cylinder.
DIAGRAM 3 -- TESTING DIRECTIONAL VALVE
DIAGRAM 4 -- TESTING WITH A "T"
CONNECTION
Sheet No.
3 of 3
Rev. 3
Date: 27 Aug. 1996
