Precautions To Be Taken - Komatsu PC20R-8 Shop Manual

REMOVAL AND INSTALLATION
PRECAUTIONS TO BE TAKEN WHILE WORKING
H When dismantling or installing a part, always take the following general precautions.
1. Precautions for removal operations
If not otherwise indicated, lower the work equipment until it rests on the ground.
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If the coolant liquid contains an anti-freeze substance, follow the instructions given for drainage.
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After having removed flanges and tubes, insert plugs to prevent impurities from entering.
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Before removing a cylinder, fully retract the piston and tie it with wire.
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Use a sufficiently large container to collect the oil.
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Before removing a part from the machine, check the alignment reference marks which show the correct in-
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stallation position. If necessary add further marks to avoid incorrect installation.
While dismantling the connectors, always grasp them firmly to avoid undue strain on the wiring.
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If necessary, attach markers to the wires and tubes to avoid muddling them up during installation.
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Check the number and height of the adjustments to a given clearance and store them in a safe place.
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When raising the machine or some parts of it, use adequate equipment for the weight of the part concerned.
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When using screws or eyebolts to remove items of the machinery, screw them alternately, and as deeply as
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they will go.
Before removing a piece, clean the surrounding area and, after removal, cover the area to prevent dirt or
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dust from gaining entrance.
2. Precautions to be taken during installation
. Tighten nuts and screws with the specified tightening torques.
. Install the flexible hoses, taking care not to entangle or twist them.
. Bend the cotter pins and stops in such a way as to secure them.
. When coating the threads with adhesives, clean the piece to remove oil and grease, then apply just enough
adhesive to cover the threading in a uniform manner.
When applying a liquid sealant, clean the surface involved, remove residual oil and grease, check that there
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are no dents or dirt, then apply the liquid sealant in a uniform manner.
Clean all the parts, remove dirt, rust, burrs, or dents.
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Apply a film of engine oil over all the moving parts.
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Apply a film of anti-friction grease (ASL800040) over all surfaces assembled with pressure, to avoid sticking.
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. After having mounted the snap-rings, check that they are firmly positioned in their seatings.
. When installing electrical system jacks, remove any oil, dust or water that may have penetrated into them,
then connect them firmly.
If using eyebolts, check that they are not distorted, screw them in fully, and then align the eye with the hoist-
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ing hook.
Mount the flanges in a uniform manner, and tighten the screws in criss-cross sequence, to avoid excessive
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pull on one side only.
3. Precautions to be taken on completion of removal and installation operations.
. If the coolant liquid has been drained away, close the drainage plug and add new liquid up to normal level.
Start the engine to circulate the liquid throughout the cooling system and then top up the level once more.
When the hydraulic equipment has been dismantled, add engine oil to the indicated level. Start up the en-
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gine to circulate the oil in the hydraulic circuits, and then top up to the indicated level.
If hoses or hydraulic equipment, such as hydraulic cylinders, pumps, motors, solenoid valves and valves,
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are removed for repairs or substitution, bleed air from the hydraulic circuits after having re-assembled the
machine.
H For details, see «20. TESTING AND ADJUSTMENTS».
After having re-assembled cylinder joints or cylinders, or work equipment articulations, lubricate thoroughly.
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PRECAUTIONS TO BE TAKEN WHILE WORKING
PC20R-8 PC27R-8