6
EATON CORPORATION Fluid Power
Test Procedure to Evaluate Fluids in Piston Pumps Technical Data V-PUPI-TS022-E March 2009
The type of fluid being tested
will determine pressure, speed,
and temperature. See Table 1.
Run for 50 to 55 hours at rated
pressure (pressure compensator
cut-off), rated speed, and rated
temperature.
Repeat the pump performance
check and record the results on
the Pump Performance Check
Record (page 11).
After completion of the 50-hour
cut-off test, inspect valve plate
and photograph the running
surface.
Fail criteria is material transfer,
or cavitation and/or erosion
damage. Slight cavitation/
erosion may be observed at the
output metering groove area of
the valve plate (Figure 5).
Re-assemble the pump and
repeat the pump performance
check. Record the results on the
Pump Performance Check
Record (page 11).
Fifty-Hour Pressure
Cutoff Test
Two Hundred-Hour
Cyclic Test
Re-Assembly
Re-assemble the pump per
Vickers Overhaul Manual M-
2210-S while lubricating all parts
with the fluid to be tested.
Test Pump Re-Installation
Install the test pump back into
the test circuit per Figure 1 and
fill the pump case with pre-
filtered test fluid.
Follow NFPA T2.13.1 R3 - 1998
procedure when changing from
one hydraulic fluid to another in
the test stand, or consult the
fluid supplier for any other
specific recommendations.
Test Fluid Filling
Measure the following on the
test fluid as received from the
drum. Record the results on the
Test Fluid Record (page 13).
• Viscosity cSt @ 40°C
• Water content wt % (0.03%
max. – only for non-water
containing hydraulic fluids)
• Cleanliness level ISO Code
• Spectrographic analysis for at
least the following elements
(ppm): P, Zn, Ca, K, Ba, B, Si,
Fe, Cu, Pb, Sn
• Total Acid Number (TAN)
mg/KOH (Report only for
vegetable and synthetic
environmentally acceptable
hydraulic fluids, and poly-
olester fire resistant hydraulic
fluids.)
After transferring the test fluid
from the drum to the reservoir
using a filter cart to assure fluid
cleanliness, report the following:
• Water content wt %
• Cleanliness level ISO Code
(maintain 18/16/14 or cleaner.)
Baseline Performance Check
The type of fluid being tested
will determine pressure, speed,
and temperature. See Table 1.
Repeat the pump performance
check and record the results on
the Pump Performance Check
Record (page 11).
Test Fluid
Sequence of Operations
1 Energize 16 and 15 – puts
pump at full displacement and
some pressure set by 17.
Time: 0.75 sec.
2 De-energize 16 – puts pump
into P.C. cut-off. Relief valve
14 is used to limit peak pres-
sure. Time: 0.5 sec.
3 De-energize 15 – puts pump
at L.S. standby. Time: 0.5
sec.
4 Repeat above sequence.
Cyclic Test Procedure
Continue running the cyclic test
for at least 200 hours. The pump
must run for a minimum of 200
hours (411,400 cycles) to a
maximum of 210 hours (431,970
cycles).
Perform the pump performance
check once per day throughout
the test. Record results on the
Pump Performance Check
Record (pages 11 and 12).
Cycle/Pressure Parameters:
• 0.75 sec full flow at 90%
rated pressure.
• 0.5 sec @ cut-off (rated
pressure).
• 0.5 sec @ load sense stand-
by.
• Load sense pressure decay
rate of 6.9 to 10.3 kbar/sec
(100,000 to 150,000 psi/sec)
Total cycle time of 1.75 seconds
(2057 cycles/hr).
Figure 7 represents a typical
cycle plot.
Control Pressure
Hysteresis Check
Perform a control pressure
hysteresis check (Appendix B)
before running the two hundred-
hour cyclic test, at 100 hours
and after completion of the 200
hours.
Pay special attention to the inlet
condition. Inlet pressure must
be maintained at 1 bar absolute
(0 psig) at full flow.
Record actual hydraulic testing
cycle plot.
If a 5% or greater flow loss is
found at rated conditions during
the test, stop the test and disas-
semble the pump for inspection.
Inspect valve plate and photo-
graph the running surface. Fail
criteria is material transfer, or
cavitation and/or erosion dam-
age. Slight cavitation/erosion
may be observed at the output
metering groove area (Figure 5).
Re-assemble the pump if parts
appear acceptable.
Pump Inspection
After completion of the 200-hour
cyclic test, disassemble test
pump and inspect as follows:
• Valve plate running face –
inspect surface finish visually
and photograph. (Figure 5)
• Cylinder barrel running face –
inspect surface finish visually.
(Figure 5)
• Swashplate running face –
inspect surface finish visually.
(Figure 5)
• Swashplate (yoke) bearing
journals – inspect visually.
• Cradle (saddle) bearings –
inspect visually. (Figure 5)
• Bias and control piston/rod –
inspect visually. (Figure 6)
• Hold-down arms and shoe
face – inspect visually.
• Shaft seal and mating shaft
surface – inspect visually.
• Measure land diameters and
width on both control spools
of the compensator. (Figure 6)
• Measure piston/shoe endplay
and piston diameter and cylin-
der barrel bores at top, middle
and bottom of piston. Record
results on the blank Piston/
Bore Record (page 15).
• Shoe cage – inspect visually.
• Shaft and shaft bearings –
inspect visually.
• Photograph any worn parts.