HEAD 2457494 - Caterpillar

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 attachments have been lowered, 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.
Hydraulic System
Hydraulic oil pressure can remain in the hydraulic system on this machine after the engine and pump have been stopped. Serious injury can result if this pressure is not released before any service is done on the hydraulic system. In order to prevent possible injury, release the hydraulic system pressure before working on any fitting, hose, or hydraulic component.Lower all work tools to the ground before service is started. If the hydraulic system must be serviced, tested, or adjusted with the work tool in the raised position, the work tool and lift cylinders must be supported properly.Always move the machine to a location away from the travel of other machines. Be sure that other personnel are not near the machine when the engine is running and tests or adjustments are being made.
Park the machine on a hard, smooth, level surface. The location should also be dry and free of debris.
Permit only one operator on the machine. All other personnel should be kept away from the machine.
If the machine is equipped with a ride control system, place the ride control system into “Service”.mode. Refer to “Ride Control” in this Operation and Maintenance, "Operator Controls" section.
Illustration 1 g02727672
Position the bucket or the work tool just above the ground at a slight downward angle. This position will ensure that the head end of the lift cylinders is pressurized.
Engage the parking brake.
Turn the engine start switch to the OFF position.
When the engine has stopped, turn the engine start switch back to the ON position so the pilot oil can reach the main valve.
Move the implement lockout switch to the UNLOCKED position.
Move the lift control lever to the FLOAT position and the tilt control lever to the TILT BACK position at the same time. This action allows the bucket or the work tool to tilt back while the boom is lowered. The bottom of the bucket or the work tool should rest flat on the ground. The weight of the linkage should be supported by the ground. The pressure from the head end of the lift cylinders and from the ride control accumulator is now vented to