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. |
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Two lift load control valves are used. The control valve (if equipped) is used to hold the lift arms in place in case of a hose failure in the lift circuit.
One lift load control valve is located on each lift cylinder.
If there is a loss of hydraulic power, perform the following procedure to lower the lift arms to the ground.
- Place the hydraulic lockout switch in the UNLOCK position.
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| Illustration 1 | g00832869 |
- Turn the engine start switch key to the ON position and crank for five seconds.
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| Illustration 2 | g00730472 |
- Leave the key in the ON position.
- Slowly tap the joystick control for the loader into the FLOAT position in order to lower the bucket to the ground.
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| Illustration 3 | g00832186 |
Manual Lowering of the Loader Bucket
Perform these steps if your machine is equipped with a pilot operated joystick for the loader.
If there is no electrical power or the accumulator is not charged, the loader cannot be lowered with the joystick control. The loader must be lowered manually.
The loader control valve is located on the right side of the machine under the cab floor.
Keep personnel away from the front of the machine.
- Remove the floorplate and remove the cover for the parking brake in order to gain access to the loader control valve.
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| Illustration 4 | g00742336 |
- The bolt that is used to manually lower the loader bucket is located in the packet with this manual. The packet is identified with the part number 205-6388 Bolt .
- Remove the pilot supply line (1) .
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| Illustration 5 | g00742334 |
- Slowly thread the 205-6388 Bolt (2) in the top of the loader valve. The lift arms will lower to the ground.
- Make the necessary repairs before you operate the machine.
Lowering a Loader with Lock Valves
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| Illustration 6 | g00833068 |
The load control valve (if equipped) for the loader is located on each lift cylinder.
The load control valve for the loader is used to hold the loader in place in case of a hose failure in the lift circuit.
To lower the loader to the ground, perform the following procedure.
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| Illustration 7 | g00514917 |
- Install a 6 mm (0.25 inch) hose onto the purging screw. Route the other end of the hose into a suitable container in order to drain the oil.
- Loosen the purging screw slightly and allow the oil to drain until the loader lowers to the ground. Tighten the purging screw after the loader is on the ground.
Lowering the Boom
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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. |
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Perform the following steps if your machine is equipped with pilot operated joysticks for the backhoe.
If there is a loss of hydraulic power, perform the following procedure to lower the boom to the ground.
- Place the hydraulic lockout switch in the UNLOCK position.
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| Illustration 8 | g00832869 |
- Turn the engine start switch key to the ON position and crank for five seconds.
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| Illustration 9 | g00730472 |
- Leave the key in the ON position.
- 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 front of the machine.
- Remove the floorplate in order to gain access to the boom control valve.
Note: The foot pedal must be removed in order to remove the floorplate.
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| Illustration 10 | g00832118 |
- 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 on machines that are equipped with a six bank valve.
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| Illustration 11 | g00833086 |
View from the seat | |
- 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 Caterpillar dealer for the proper relief valve setting.
- Make the necessary repairs before you operate the machine.
Lowering a Boom with Lock Valves
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| Illustration 12 | g00287734 |
The boom load control valve (if equipped) is located on the boom cylinder.
The boom load control valve is used to hold the boom in place in case of a hose failure in the boom circuit.
To lower the boom to the ground, perform the following procedure.
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| Illustration 13 | g00514917 |
- Install a 6 mm (0.25 inch) hose onto the purging screw. Route the other end of the hose into a suitable container in order to drain the oil.
- Loosen the purging screw slightly and allow the oil to drain until the boom lowers to the ground. Tighten the purging screw after the boom is on the ground.