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The trouble is that the drill pipe drops slowly after shutdown. The reason may be that the floating solenoid valve is stuck or the brake slips.

If the floating solenoid valve is stuck, the drill pipe may drop slowly even without stopping the machine. At this time, the floating solenoid valve can be disassembled, the spool can be disassembled and cleaned, or the valve can be replaced.

After long-term wear and tear of the brake pad, it will not provide enough braking force, which will cause braking failure and slow down of the drill pipe. At this time, the brake pad can be replaced.