KIT-SEAL 3995668 - 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 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.
Lower the work tool to the ground.
Shut off the engine.
Turn the engine start key to the ON position. Do not start the engine.
Push the hydraulic lockout to the UNLOCKED position. This will activate the hydraulic functions.
Move the control levers through the full range of travel. This will relieve any pressure that may be present in the implement hydraulic system. Note: Actuate the accumulator arms by pressing the OPEN and CLOSE buttons that are located on the control lever.
Depress the brake pedal repeatedly. This will relieve any pressure that may be present in the brake hydraulic system.
Pull the hydraulic lockout to the LOCKED position. This will deactivate the hydraulic functions.
Turn the engine start key to the OFF position.
Depress the breaker relief valve that is located on the machine in order to relieve system pressure.
Slowly loosen the hydraulic oil filler cap in order to release system pressure.
Tighten the hydraulic oil filler cap.
The pressure in the hydraulic system has been released. Lines and components can be removed.