Boom Actuator Service (Machines with Serial Numbers Above 260000000)
IMPORTANT: Do not dismantle, repair or modify the boom actuator. Internal components are not available for the actuator. If an actuator is damaged or worn, replace actuator.
CAUTION
Actuator Air Bleeding If actuator freeplay is excessive, air bleeding of the actuator should be performed using the following procedure: 1. Thoroughly clean the exterior of actuator to prevent contaminates from entering the actuator.
During and after operation, the actuator may be very hot. To avoid possible burns, allow the actuator to cool before working on it. Actuator Circuit Protection Each boom actuator is protected internally by a thermal circuit breaker. In case of actuator overheating, the thermal breaker will trip, causing the actuator to cease functioning. Once the actuator cools to appropriate operating temperature, the actuator thermal breaker will reset to allow actuator operation to resume. A separate 30 amp thermal breaker also protects each boom actuator circuit. These thermal breakers are located at the machine fuse panel and will prevent circuit operation if overloaded. The thermal breakers reset automatically.
2. Make sure that the actuator cylinder is fully retracted. IMPORTANT: To prevent actuator damage, use vise with protective jaws when clamping actuator. 3. Place the actuator in a vise making sure that actuator is clamped in the area identified in Figure 49. Use just enough clamping force to hold the housing securely. Make sure that the reservoir plug is orientated up.
CAUTION The actuator reservoir is pressurized. If the reservoir plug is removed too quickly, oil under pressure can be ejected from the actuator.
Actuator Freeplay Inspection
4. Slowly loosen and remove the reservoir plug at the top of the reservoir.
Over time, actuator operation may be affected by air captured in the reservoir oil. An excessive amount of air in the actuator oil will allow excessive actuator freeplay. Excessive freeplay will allow spray boom bouncing when driving over severe terrain.
5. Using a light through the plug hole, confirm that the reservoir oil is clear. If the oil appears milky, air is entrained in the reservoir oil. Keep the actuator vertical with the plug removed for approximately 15 minutes to allow the air to separate from the oil.
Measure actuator freeplay using the following procedure:
6. When oil appears clear, use a 12 volt DC power supply to power the actuator and extend the cylinder completely.
1. Move the vehicle to an open area and lower the spray booms to the spray position. 2. Lift up on the boom at the last triangular gusset with a 25 pound (11.4 kg) force. Support boom in that position. 3. Using a non–permanent felt tipped marker, mark the cylinder rod at the outside of the cylinder seal. 4. Release the spray boom and allow it to return to the spray (fully lowered) position. 5. Determine the actuator freeplay by measuring the distance from the mark on the cylinder rod to the cylinder seal. The freeplay should be less than 0.100” (2.5 mm). If excessive freeplay is found, bleed air from actuator.
Spray System
IMPORTANT: To ensure proper reservoir pressure, make sure that cylinder is extended before installing reservoir plug. 7. Install the reservoir plug and torque from 45 to 60 in– lb (5.1 to 6.8 N–m). 8. If reservoir oil was milky, use power supply to contract and extend the actuator cylinder 3 times. Repeat steps 2 through 7 until oil is clear. 9. When actuator oil is clear and plug has been installed, use power supply to fully contract the actuator cylinder. Remove actuator from vise and install on machine.
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Rev. A
Multi Pro 5700–D