21
TOP & BOTTOM RAM continued
Ram not holding under load.
When you let go of the controls the cylinder
movement must stop.
We do not advise that a machine is left
extended unattended for any great length of
time (over night etc.) It is normal to expect
some slight creep over time, but during
normal operating conditions the ram should
hold the load and not move once the lock
valve cartridge has closed. (This may take up
to 1-2 sec after the directional valve has been
returned to the centre position. The pilot
pressure holding the valve open must be
allowed to drain back to tank to allow the lock
valve to seat fully).
When a cylinder is not holding you must
decide which part has failed.
• Cylinder Piston Seal
• O/C valve (or check valve)
• Emergency Lowering cartridge (if fitted)
The best and quickest way of establishing
this are by removing all hoses (carefully) to
see where oil is leaking out.
If oil is coming out from :
• The Emergency lowering cartridge is
faulty. Clean or replace
• The O/C (or check valve) is faulty.
Clean, adjust relief valve or replace
(Note that check valves are non
adjustable and can only be cleaned or
replaced)
• Replace the Piston seal kit. Oil is
passing the piston and escaping out of
the annular port which have no lock
valve fitted
For clarity the drawing shows only one hose
to each service. In reality you have two
hoses, one for the Cage controls and one for
the ground controls. It is only the emergency
lower which has one hose.
MAINTENANCE PROCEDURE
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