Gradall 534B (9020-7317) Service Manual - Manual (Page 122)

Hydraulic Flow Meter. This meter measures pump
flow under varying pressure conditions. You can
measure actual pump output, both with no
resistance and with resistance imposed against it.
Contact your Gradall Materials Handler
Distributor.
HOW TO TEST PUMP FLOW
Insert a flow meter into the output (pressure port) of
the pump, and observe actual pump flow. Tests
should be made for volume with no resistance and
then with resistance equal to the pump relief valve
setting. An inefficient or worn pump may pump full
volume of oil under no load, but almost nothing the
under full resistance.
Flow meter readings will show less than the
theoretical rating because of back pressures, the
thinning out of oil because of temperature, and the
resistance caused by relief valves. At 180ø F., flow
meter reading will show less gallonage than at 120°
F. As a pump works, the pump output will also be
reduced depending upon the degree of internal
wear.
GRADALL LOED MATERIALS HANDLER 534B TESTING AND ADJUSTING
TOOLS NEEDED TO TEST SYSTEM
Other Tools Needed:
5/16" Allen wrench for pilot valves.
3/16" Allen wrench for steering valve.
Volt Ohm-Ampere Meter.
Selection of wrenches and screwdrivers.
Hydraulic Pressure Gages. We recommend a
0-1000 psi gage and a 0-5000 psi gage for ease of
testing. Kit 7713-4197 includes both gages and a
selection of adapters and hoses.
TEST PORTS
The Gradall Materials Handler has test ports for
main relief and circuit relief testing. Mini-check
type of test ports have a one-way check valve to
prevent loss of oil whenever the cap is removed. As
the gage (or hose) adapter is installed and tightened,
the one-way check is unseated and the circuit is
available for testing.
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