Flo-Check
®
USB Hydraulic System Analyzer
Installation & Programming Instructions
Page 24
Form No. 05-SGN-PM-00191 02/12
2. Select Run and/or Record on the PC (see Recording Measurements to a File on page 8).
3. With the load valve fully open, the extension or retraction times can be set, veri
fi
ed and/or logged in the
circuit. Inches per Minute = (231 × GPM) / SQ IN
4. Force can also be checked by checking the pressure when the cylinder is at the end of its stroke.
Force = Pressure × Area
a. If all components are in good operating condition, pressure and
fl
ow measurements should be the
same as in the Pump Test.
b. If a decrease in
fl
ow or pressure in any control valve position is noted, leakage is indicated.
c. If the decrease in
fl
ow is the same with the control valve(s) in all positions, it indicates the relief valve
is at fault. (Note: This can also indicate some other leak is present in the control valve such as a
defective casting, damaged seals, or worn valve position detents – but always check the relief valve
FIRST.)
d. If the relief valve is operating normally, see Directional Control valve (DCV) Test.
e. A decrease in pressure at the cylinders full stroke could indicate worn piston seals
.
V. Hydrostatic Transmission Diagnostics
Install the Flo-Check into the system between the pump discharge port and the inlet of the hydraulic motor.
PV
Flow (Bi-directional)
Reservoir
Case Drain
MF
Flo-Check
FIGURE 11 -
Hydrostatic Transmission Test
A. Pump
1. Open the Flo-Check loading valve fully to read maximum pump
fl
ow at zero pressure.
2. Select Run and/or Record on the PC (see Recording Measurements to a File on page 8), then close the
loading valve to increase pressure from zero pressure to rated or maximum pump pressure to determine
pump condition.
3. The
pump
fl
ow at rated pressure can now be checked against the pump manufacturer’s speci
fi
cations. A
decrease in
fl
ow from zero pressure to maximum pressure indicates a drop in volumetric ef
fi
ciency.
B. Motor Test No Load
1. Open the Flo-Check loading valve fully to read maximum pump
fl
ow at zero pressure.
2. Select Run and/or Record on the PC (see Recording Measurements to a File on page 8).
3. Put one control valve in the forward operating position. (If there are multiple valves, only one control valve
should be in an operating position at any one time.)
