MTD 2010 Shop Manual page 25

For Parts Call 606-678-9623 or 606-561-4983
2,000 PSI
1.5 lpm
Figure 3.19
Pump By-pass Settings
Pump Tonnage
718-04127 21,25 and
27
718-04729 27 ton HP
pump
718-04128 33
K. Record the rated flow rate from the pressure mode flow capacities chart on to the worksheet.
Interpreting the test results:
NOTE: The engine governor should hold engine RPMs constant during the test.
• If the pump fails to produce the base-line flow rate, but engine RPM is 3,500, there is problem with the
drive system (engine coupler) or the pump.
• The flow should be within 1 GPM (3.8 LPM) of the rated capacity.
• If flow droops more than 1 GPM (3.8 LPM), and the engine RPM falls, there is an engine problem
• If pressure fails to build, there is a problem with the drive system (engine coupler, keys or the pump).
• If flow drops more than 1 GPM (3.8 LPM), the engine RPM does not change, and the engine exhaust note
does not change, there is a problem with the drive system (engine coupler and spider) or the pump.
• If base-line flow is within 1 GPM (3.8 LPM), pressure builds to 2,000 PSI (138 Bars) when the needle
valve is closed; the pump, engine, and drive are working properly.
• To identify drive problems examine the engine coupler and spider.
• If the pump fails to switch from volume mode to pressure mode within 100 PSI of the rate by-pass setting,
the pump is bad.
By-pass
Pressure
+ 100 PSI
500 (34 bar)
1,000 (69
bar)
700 (48 bar)
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F. Slowly close the needle valve to build 2,000 PSI (220
Bars). See Figure 3.19.
Do NOT exceed 3,200 PSI (220
Bars). This test is performed up-
stream of the relief valve in the log
splitter hydraulic system, rendering the relief
valve ineffective during the test. Over-load-
ing the system will damage the pump.
G. Record the engine RPMs on the worksheet.
H. Record the flow meter reading on the worksheet.
I. Record the pressure reading on the worksheet.
J. IMMEDIATELY open the needle valve, then turn-off
the engine.
Pressure Mode Flow Capacities
Pump Tonnage
718-04127 21,25 and
27
718-04729 27 ton HP
pump
718-04128 33
Hydrualic Diagnosis
GPM/LPM
+ 0.5 gpm
1.5 (5.5 lpm)
3 (11 lpm)
3 (11 lpm)
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