Handle type tensioner brake will not loosen without pressure brake system: oil pump reverses rotation or oil pump does not output liquid; electro-hydraulic proportional device on the relief valve spool stuck, damping hole blocked; oil pump suction port is not flat, suction filter blocked; pressure buckle tensioner pressure valve internal dust, conical valve can not be closed. Tensioner manufacturer's treatment: correct the direction of rotation of the pump to eliminate the oil pump failure; disassemble and clean the relief valve, requiring the spool to move flexibly in the valve body, blow the damping hole with compressed air; clean the filter element and check whether the suction pipe is blocked; disassemble the pressure valve and take the cone valve for cleaning.