Replacing hydraulic oil while its temperature is high
• The higher the oil temperature is, the softer the oil is, and the smoother the oil runs. Also, the sludges are
easily discharged from the circuit. Perform the replacement while oil temperature is high.
• Old hydraulic oil needs to be drained as much as possible when replacing.
NOTICE
Old hydraulic oil contaminates the new one if it is mixed since it contains contaminants and sludg-
es, and the service life of the hydraulic oil is shortened.
REMARK
Drain the old hydraulic oil not only from the hydraulic tank but also from the filter and drain plug in the cir-
cuit.
Flushing operation
• Flushing is required to completely dislodge the contami-
nants and sludges, and existing oil containing those inside
the hydraulic circuit after disassembling and assembling,
and when replacing the oil with the new one.
• Normally, flushing is performed twice. Primary flushing is
performed by using the flushing oil (1) and the secondary
flushing is performed by using the specified hydraulic oil.
Cleaning operation
Perform oil cleaning to remove the contaminants and sludges in the hydraulic circuit after repair of the hydraulic
device (pump, or control valve) or during operation of the machine.
REMARK
The oil cleaning equipment can remove the ultra fine (approxi-
mately 3 μm) particles that the filter built in the hydraulic equip-
ment cannot remove. So, it is very effective device.
00 INDEX AND FOREWORD
PRECAUTIONS FOR HANDLING HYDRAULIC EQUIPMENT
PC290LL-11
00-43
