Specifications

046-08OP-001D S/N 046050010021 - UP

Boom Stop Valve Operation and Adjustment

The Boom Stop system stops the boom winch from hauling-in when the boom is vertical, preventing overloading of key

machine components. Incorrectly adjusting, or defeating the boom stop valve could result in serious equipment damage,

personal injury, or even death. Its operation must be check and verified daily

Figure 31: Boom stop valve located behind access cover in Left Hand tower.

• To check the operation, boom in slowly taking care not to over tension the boom lines when the boom goes vertical.

When the boom is vertical, the boom winch should stop. No increase in tension should occur once the boom comes into

contact with the left hand tower. If the boom winch does not stop and continues to increase the cable tension, STOP the

operation at once and lower the boom to release the tension. Adjust the boom stop valve as set out below.

• Raise the boom vertical so that it is JUST in contact with the tower; the boom kick-out rod is fully retracted into the

tower. Do not over tighten the lines to the point that the boom or structures are overly stressed.

• Remove the boom stop valve access panel from the tower.

• Loosen the boom stop valve nuts.

• Move the valve so that it just contacts the boom kick-out rod.

• Move the valve an additional 10 mm (3/8-in) towards the boom so that the valve's piston is fully depressed.

• Tighten the valve in position with the valve nuts.

• Test the boom stop valve to see that it works properly. Lower the boom until the boom stop valve piston is free from the

kick-out rod.

• Replace the boom stop valve access panel from the tower.

• Boom in slowly taking care not to over tension the boom lines when the boom goes vertical. When the boom is vertical,

the kick-out rod will move the boom stop valve piston in 9.5 mm (3/8 in), and the boom winch should stop with the

boom vertical. No increase in tension should occur once the boom comes into contact with the left hand tower, readjust

the boom stop valve as required.

Boom Stop

Valve

035-09-12-001