FAN AS 3756142 - Caterpillar

Pressure Release Procedure
Personal injury can result from hydraulic oil pressure and hot oil.Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system.Make sure all of the work tools have been lowered to the ground, and the oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.
Start the engine.
Move the machine to a smooth horizontal location that is away from other machines and personnel.
Make sure that all hydraulic functions are operating properly.
If all the hydraulic functions are operating properly, perform Steps 6 through 17 for the hydraulic system pressure release for a live engine.
If any hydraulic functions are not operating properly, perform the steps for the hydraulic system pressure release for a dead engine.
Lower all attachments to the ground except for the blade. The blade is to remain approximately 0.6 m (2.00 ft) from the ground.
Permit only one operator on the machine. Keep all other personnel away from the machine.
Engage the parking brake.
Stop the engine.Note: Do not start the engine at this time.
Turn the ignition key to the ON position.
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Make sure that hydraulic shutoff switch (2) is in the position that allows operation of the implements.
Move ripper control levers (3) to all positions so that the pressure in the ripper cylinders is released.Note: The blade will slowly lower as the ripper commands are given.
Once the ripper cylinders are fully relieved of pressure, shake out blade controls (1) for at least 1 minute after blade reaches ground level to ensure that all cylinder pressure is released.
Turn the ignition key to the OFF position.
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Press check valve (3) in order to release the hydraulic tank pressure.
Properly lock-out / tag-out machine.
The pressure in the system has now been released and lines or components can be removed.Pressure Release Procedure for Dead Engine
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Remove the floor mat. Remove floorplates (1) .
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Loosen the nut. Turn out bolt (2) to approximately one revolution in order to release the hydraulic system pressure.Note: Tighten the nut on bolt (2) to a torque of 20 N m (15 lb ft).