Hitachi EX20UR-2 Manual page 8

PRECAUTIONS FOR DISASSEMBLING
AND ASSEMBLING
Preparations for Disassembling
• Clean the Machine
Thoroughly wash the machine before bringing it
into the shop. Bringing a dirty machine into the
shop may cause machine components to be con-
taminated during disassembling/assembling, re-
sulting in damage to machine components, as
well as decreased efficiency in service work.
• Inspect the Machine
Be sure to thoroughly understand disassembling
procedures beforehand, to help avoid incorrect
disassembling of components as well as the pur-
chase of unnecessary service parts.
Check and record the items listed below to help
prevent problems from occurring in the future.
- The machine model, machine serial number, and
hour meter reading,
• Reason for disassembly (symptoms, failed parts,
and causes).
• Clogging of filters and oil or air leakages, if any,
• Capacities and dirtiness of lubricants,
Loose or damaged parts.
• Prepare and Clean Tools and Disassembly Area
Prepare tools to be used and areas for disassem-
bling as well as for disassembled parts. Clean the
tools and areas.
Precautions for Disassembling and Assembling
• Precautions for Disassembling
Be sure to provide appropriate containers for
draining fluids.
• Use matching marks for easier reassembling.
• Be sure to use specified special tools, when so
instructed.
• If a part or component cannot be removed after
removing its securing nuts and bolts, do not at-
tempt to remove it forcibly. Find the cause(s),
then take appropriate measures to remove it.
• Orderly arrange disassembled parts. Put marks
and tags on them as necessary.
Store common parts, such as and bolts with ref-
erence to where they are to be used and in a
manner that will prevent loss.
• Inspect contact or sliding surfaces of disassem-
bled parts for abnormal wear, sticking, or other
damage.
• Measure and record degrees of wear and clear-
ances.
• Precautions for Assembling
• Be sure to clean all parts and inspect them for
any damage. If any damage is found on a part,
repair or replace it with a new one.
• Dirt or debris on contact or sliding surfaces may
shorten the service life of the machine. Take
care not to contaminate any contact or sliding
surfaces of the parts to be assembled.
• Be sure that liquid-gasket-applied surfaces are
clean and dry.
• If an anti-corrosive agent has been used on a
new part, be sure to thoroughly clean the part so
as to remove the agent.
• Utilize matching marks when assembling.
• Be sure to use designated tools to assemble
bearings, bushings and oil seals.
• Keep a record of the number of tools used for
disassembling/assembling. After assembling is
complete, count the number of tools, so as to
make sure that no tools are left in the assembled
components.
I
GENERAL INFORMATION / Precautions for Disassembling and Assembling
W01-01-01