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SLEW MOTOR
The motor is a high torque low speed
hydraulic motor. The motor can be
unbolted from the slew drive to check for
leakage. Full seal kit is available with
overhaul instructions.
3 and 4 indicate the hoses going to the
cage controls.
GENERAL TESTS OF LOAD
HOLDING VALVES
You have seen that all critical
movements rely on 2 components for
safety
• The lock valve on the cylinder
• The closed centre on the valve block
The valve blocks used have very low
leakage rate (that is why we can rely on it
for the slewing cage ram which have no
lock valve).
How do you know if you are holding on
the valve block and not on the cylinder
lock valve ?
Simple - With the pump not running.
operate the valve block as if you were
going to close the ram up. If you get
cylinder movement you know you have a
leaking load holding valve on the
cylinder.
Do not use a machine where the load
holding valve has failed.
BLEEDING
The hydraulic system needs no special bleeding.
If you have stripped a cylinder down or removed
hoses for repair, just operate the cylinder fully in
and fully out and the system is operational.
REMEMBER
Keep it clean - Replace filter and oil regularly - Make sure the oil you put in the tank is
clean - Never fill oil using dirty cans - Remember you use no oil - If you have to
replace oil you have a leak - If you work regularly below 0 deg C and use low viscosity
oil, do not forget to replace the oil for regular grade in the summer to prevent oil leaks
from cylinders and hose ends - Keep a log of relief valve settings to monitor pump
performance - If you have a problem the first thing to do when you arrive is to fit a
pressure gauge to see what is going on. Do not rely on the sound of the pump !
SLEWING CAGE RAM
Do not operate the slewing basket ram valve
lever without the pump turning. If you operate
the valve lever you can push the basket from
side to side. You have now entered air into the
system and the basket will not stay put during
transport.
If this should happen, just move the valve lever
with the pump running, moving the basket from
side to side will fill the cylinder with oil and the
basket will lock in place, when you release the
lever
MAINTENANCE PROCEDURE
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