PISTON AS 7W2512 - Caterpillar

Personal injury or death can result from boom lowering.The boom can drop when lowering it with the engine stopped.Keep all personnel away from the boom drop area when lowering the boom with the engine stopped.Be sure no one is under or near the front linkage before manually lowering the boom.
Lowering the Equipment with the Accumulator Charged
If electrical power is available and the accumulator is charged, the boom can be lowered from the operator station with the boom control lever.
Turn the engine start switch key to the ON position.
Unlock the work tool lockout control.
Slowly, move the lift lever to the LOWER position in order to lower the boom slowly. If the boom does not lower, the accumulator is not charged. If the engine has been off for more than 10 minutes and the engine is operable, start the engine and move the lift lever to the LOWER position.If there is no electrical power, the boom must be lowered manually. Use the following procedure.Lowering the Equipment with the Accumulator Discharged
If there is no electrical power or the accumulator is not charged, the boom cannot be lowered with the boom control lever. The boom must be lowered manually.
Illustration 1 g02542316The bypass valve is located at the center articulation joint of the machine on the right side.The lift arms will start lowering when the bypass valve is opened.Keep personnel away from the front of the machine.Slowly turn the square stem of the bypass valve in a clockwise direction. The square stem should be rotated 90 degrees.The lift arms will lower to the ground.