Hyundai HL955 Manual page 545

2)
GENERAL PRECAUTIONS
(1) Clean room with no dust is recommended for maintenance. Because hydraulic components
are precision, and have minute clearance. Tool and wash-oil must be clean, too. Handle
them carefully.
(2) At removing control valve from the machine, wash around the piping port, and neither dust
nor water should go into inside with plugging. It is same at attaching the machine.
(3) Prepare the required parts by checking structure figure before assembly. There are parts
which are supplied with only sub-assembly part, so check the parts list before assembly.
3)
PRECAUTIONS FOR DISASSEMBLY
(1) Handle the components carefully not to drop them or bump them with each other as they are
made with precision.
(2) Do not force the work by hitting or twisting as burred or damaged component may not be
assembled or result in oil leakage or low performance.
(3) When disassembled, tag the components for identification so that they can be reassembled
correctly.
(4) Once disassembled, O-ring and back-up rings are usually not to be used again.(Remove them
using a wire with its end made like a shoe-horn. Be careful not to damage the slot)
(5) If the components are left disassembled or half-disassembled, they may get rust from moisture or
dust. If the work has to be interrupted, take care to prevent rust and dust.
4)
PRECAUTIONS FOR REASSEMBLY
(1)
Take the same precautions as for disassembly.
(2)
When assembling the components, remove any metal chips or foreign objects and check them
for any burrs or dents. Remove burrs and dents with oil-stone, if any.
(3)
O-rings and back-up rings are to be replaced with new ones, as a rule.
(4)
When installing O-rings and back-up rings, be careful not to damage them. (Apply a little amount
of grease for smoothness)
(5)
Tighten the bolts and caps with specified torque.
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