C2356
C2351
Fixed end
Fixed end
C1336
1-31
HYDRAULIC CYLINDERS 1.4
If the boom or bucket cylinders drift down with the
control valve spools in the neutral position, and with no
external leaks in the hydraulic system, the following test
will indicate if oil is leaking by the cylinder piston seals.
With the hydraulic oil at operating temperature and a
fully loaded attachment, check that the cylinders do not
drop more than 1.5 inches every 3 minutes with the
engine off. Before performing this test, ensure the control
linkages are not binding and the hydraulic control valve
spools are centering in the neutral position. If the test has
proven excessive leak down the cylinders may be further
tested in the following manner.
1 This test must be performed with the engine running.
Remove any attachment and block the loader securely
with all 4 wheels off the ground.
2 Retract the cylinder(s) to be tested. Shut off the
engine and cycle the controls to release the hydraulic
pressure.
3 Disconnect the hose from the fixed end of the
cylinder to be tested. Cap the hose with a steel plug to
prevent system charge pressure from escaping the open
circuit and to prevent contamination.
4 Start the engine and cycle the control(s) as to retract
the cylinder. Do not over activate the controls as to place
in the detent position. Have a container can ready to catch
any waste oil to prevent environmental contamination.
5 Repeat for all both cylinders.
6 If oil leaks from the cylinder port the seals are bad
and need replacement. If no oil leaks you may need to
check the load check valves or spool wear in the
hydraulic control valve.
7 Connect the hydraulic hose to the cylinder ports if no
further servicing is required.
Testing the Piston Seals
IMPORTANT
Allowable boom or bucket cylinder drop: 1.5’’ in
3 minutes, @ loaded rating and operating
temperature.
WARNING
Never repair or tighten hydraulic lines while the
engine is operating or the system is under pressure.
WARNING
Use extreme caution when checking the hydraulic
system for leaks. Fluid under pressure can penetrate
the skin and cause serious injury. Never use your
hands to check for leaks.
Hydraulics under liftarm step
To Next Page
Loading...
Need help?
General
