Service manual

B
P–10949
HYDRAULIC PUMP
Checking The Output Of The Pump
The tools listed will be needed to do the following
procedure:
MEL10003 – Hydraulic Tester
MEL10006 – Hydraulic Test Kit
NOTE: Make sure all the air is removed from the
hydraulic system before beginning the test.
Air in the system can give an inaccurate test.
*Relief pressure must be per specification
before the test is done.
Lift and block the loader. (See Page 1–1.)
Raise the operator cab. (See Page 1–1.)
Connect the remote start switch. (See Page 1–1.)
Disconnect the OUTLET hose from the pump [A].
Connect the INLET hose from the tester to the OUTLET
of the pump. Connect the OUTLET hose from the tester
to the hose which was disconnected from the pump [B].
W–2017–0286
Put jackstands under the front axles and rear
corners of the frame before running the engine
for service. Failure to use jackstands can allow
the machine to fall or move and cause injury or
death.
Start the engine and run at low idle RPM. Make sure the
tester is connected correctly. If no flow is indicated on the
tester, the hoses are connected wrong. With the hoses
connected correctly, increase the engine speed to full
RPM.
Warm the fluid to 140°F. (60°C.) by turning the restrictor
control on the tester to about 1000 PSI (6895 kPa). DO
NOT exceed system relief pressure. Open the restrictor
control and record the free flow (GPM) at full RPM.
Push the mode switch (on the remote start switch) to
engage the front auxiliary hydraulics, the light will come
ON. Push the button (on the right steering lever) for fluid
pressure to the quick coupler (fluid pressure will go over
main relief). Record the highest pressure (PSI) and flow
(GPM). The high pressure flow must be at least 80% of
free flow.
HIGH PRESSURE FLOW (GPM)
FREE FLOW (GPM)
% =
X 100
A low percentage may indicate a pump problem.
A
CD–11093
–2–36–
853, 853H BICS Loader
Service Manual
853, 853H Service Manual #6720755 – Hydraulic System Section Part 1 of 2