Accumulator; Releasing Hydraulic Pressure With Accumulator - Komatsu PC450-8 Operation & Maintenance Manual

DETAILED CONTROLS AND GAUGES

ACCUMULATOR

The accumulator is charged with high-pressure nitrogen gas, so mistaken operation may cause an explo-
sion which will lead to serious injury or damage. When handling the accumulator, always do as follows.
The pressure in the control circuit cannot be completely removed. When removing the hydraulic equip-
ment, do not stand in the direction that the oil spurts out when carrying out the operation.
Loosen the bolts slowly.
Do not disassemble the accumulator.
Do not bring it near flame or dispose of it in fire.
Do not make holes in it or weld it.
Do not hit it, roll it, or subject it to any impact.
When disposing of the accumulator, the gas must be released. Please contact your Komatsu distributor to
have this work carried out.
This machine is equipped with an accumulator in the control
circuit. The accumulator is a device to store oil pressure for the
control circuit, and when it is installed, the control circuit can be
actuated for a short time even after the engine is stopped. Due
to this device, the work equipment lowers under its own weight,
if the control lever is moved in the lowering direction.
The accumulator is installed to the position shown in the dia-
gram on the right.

Releasing Hydraulic Pressure With Accumulator

1. Place the work equipment on the ground. Close the
crusher attachment jaws, etc.
2. Stop the engine.
3. Turn the key in starting switch to the ON position.
4. Move the safety lock lever to the free position. Move the
work equipment control lever and the attachment control
pedal to full stroke back and forth, right and left so as to
release the pressure in the control circuit.
5. Move the safety lock lever to the lock position. Lock the
control lever and attachment control pedal.
6. Turn the key in starting switch to the OFF position.
3-110
WARNING
OPERATION
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