TM 5-3825-226-24
Method of finding flow loss...
Pump flow at 100 psi...... 57.5 gpm (litre/min)*
Pump flow at 1000 psi .. -52.0 gpm (litre/min)*
Flow loss . ........ ........ 5.5 gpm (litre/min)*
Flow loss when expressed as a percent of flow loss is
used as a measure of pump performance.
If the percent of flow loss is more than 10% for test
on the machine or 15% for test on the bench, pump
performance is not good enough.
Example of finding percent of flow loss
(
gpm flow loss
Pump flow @ 100 psi
)
x 100 =
Percent of
flow loss
(
* 5.5
*57.5
)
x 100 =
9.5%
*Numbers in examples are for illustration and not
values for any specific pump or pump condition. See
Hydraulic Pump Specifications for actual pump flow of a
new pump at 100 psi and 1000 psi.
Test On The Machine
Install a 9S2000 Flow Meter. Run the engine at 2000
rpm. Measure the pump flow at 100 psi (7.0 kg/cm2)
(690 kPa) and at 1000 psi (70.0 kg/cm2) (6900 kPa).
Use these values in Formula I.
Formula I:
(
gpm @ 100 psi-gpm @1000psi
gpm @ 100 psi
)
x 100 =
Percent
of flow
loss
Test on the Bench
If the test bench can be run at 1000 psi and at full
pump rpm. find percent of flow loss using Formula I.
If the test bench can not be run at 1000 psi at full
pump rpm. run the pump shaft at 1000 rpm. Measure
the pump flow at 100 psi (7.0 kg/cm2) (690 kPa) and at
1000 psi (70.0 kg/cm2) (6900 kPa). Use these values in
the top part of Formula II. For the bottom part of the
formula, run the pump shaft at 2000 rpm. Measure the
pump flow at 100 psi.
Formula II:
(
gpm@100 psi-gpm @ 1000psi
gpm @100 psi @pump rpm
)
x 100 =
Percent
of flow
loss
Hydraulic Pump Specifications
Rotation is counterclockwise when seen from drive end.
Type of pump: Vane
For test, use SAE 10W oil at 150°F (65°C).
LARGE SECTION OF PUMP (Drive end) (Steering)
Test at Full Speed:
Output .......................... 23.0 U.S. gpm (87.1 litre/min)
at a pressure of .....100 psi (7.0 kg/cm2) (690 kPa)
with pump at ..........................................2000 rpm
with engine at ........................................2000 rpm
Output .......................... 20.4 U.S. gpm (77.2 litre/min)
at a pressure of 1000 psi (70.0 kg/cm2) (6900 kPa)
with pump at ..........................................2000 rpm
with engine at ........................................2000 rpm
Test at Half Speed:
Output .......................... 11.3 U.S. gpm (42.8 litre/min)
at a pressure of .....100 psi (7.0 kg/cm2) (690 kPa)
with pump at ..........................................1000 rpm
with engine at ........................................1000 rpm
Output.............................. 10.0 U.S. gpm (37.9 litre/min)
at a pressure of 1000 psi (70.0 kg/cm2) (6900 kPa)
with pump at ..........................................1000 rpm
with engine at ........................................1000 rpm
SMALL SECTION OF PUMP (Cover end) (Implement)
Test at Full Speed:
Output .......................... 23.7 U.S. gpm (89.7 litre/min)
at a pressure of .....100 psi (7.0 kg/cm2) (690 kPa)
with pump at ..........................................2000 rpm
with engine at ........................................2000 rpm
Output .......................... 23.0 U.S. gpm (87.1 litre/min)
at a pressure of 1000 psi (70.0 kg/cm2) (6900 kPa)
with pump at ..........................................2000 rpm
with engine at ........................................2000 rpm
Test at Half Speed:
Output .......................... 11.7 U.S. gpm (44.3 litre/min)
at a pressure of .....100 psi (7.0 kg/cm2) (690 kPa)
with pump at ..........................................1000 rpm
with engine at ........................................1000 rpm
Output .......................... 10.8 U.S. gpm (40.9 litre/min)
at a pressure of 1000 psi (70.0 kg/cm2) (6900 kPa)
with pump at ..........................................1000 rpm
with engine at ........................................1000 rpm
or
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