450E Backhoe Loader Caterpillar

Lowering the Loader Bucket

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Personal injury or death can result from a bucket falling. Keep personnel away from the front of the machine when lowering the bucket.

If there is a loss of hydraulic power, perform the following procedure in order to lower the lift arms to the ground.

1. Slowly tap the loader control lever into the FLOAT position in order to lower the bucket to the ground.

Lowering the Boom (Pilot Controls)

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Personal injury or death can result from the boom falling. Keep personnel away from the rear of the machine when lowering the boom.

If there is a loss of hydraulic power, perform the following procedure to lower the boom to the ground.

1. Place the hydraulic lockout switch in the UNLOCK position.

2. Turn the engine start switch key to the ON position and crank for 5 seconds.

3. Leave the key in the ON position.

4. Slowly tap the joystick control for the boom into the DOWN position in order to lower the boom to the ground.

Manual Lowering of the Boom

If there is not electrical power or the accumulator is not charged, the boom cannot be lowered with the joystick control. The boom must be lowered manually.

The boom control valve is located under the cab floor.

Keep personnel away from the rear of the machine.

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Illustration 1	g01207044

1. Remove the floorplate in order to gain access to the boom control valve.

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Illustration 2	g01959887

2. Loosen the nut that locks down the stem. Slowly turn the stem of the relief valve in a counterclockwise direction. The boom will lower to the ground.

   Note: The boom valve will be the second valve.

3. Slowly turn the stem of the relief valve in a clockwise direction. Rotate the stem until the stem bottoms out in the hole. Tighten the nut in order to lock down the stem. This procedure will change the setting for the relief valve. Contact your Cat dealer for the proper relief valve setting.

4. Make the necessary repairs before you operate the machine.

Lowering the Boom (Dead Engine)(Mechanical Controls)

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Personal injury or death can result from the boom falling. Keep personnel away from the rear of the machine when lowering the boom.

If there is a loss of hydraulic power, perform the following procedure to lower the boom to the ground.

1. Slowly operate the boom control lever into the "Boom Lower" position in order to lower the backhoe bucket to the ground.