The weak or slow lifting of a ISUZU Truck with Crane is usually caused by low or no pressure in the hydraulic system. In this situation, the operator should immediately stop the operation and continue only after troubleshooting. The following is a guide for diagnosing and resolving common causes of insufficient hydraulic pressure.
Firstly, check if the hydraulic pump is supplying oil. If the pump does not supply oil, possible reasons include incorrect pump rotation direction, severe wear or damage to internal components, excessive suction resistance due to filter blockage or high oil viscosity, or air leakage in the suction pipeline. In this case, the overflow valve should be disassembled and cleaned, and the spring should be inspected or replaced to restore its normal operation.
Next, check if the entire hydraulic system can establish normal pressure. Insufficient pressure in specific pipelines or hydraulic cylinders may be caused by blockages in pipelines, throttle valves, or directional control valves. To identify the problem, each part should be checked step by step - simultaneously checking pressure and oil flow - to identify and remove any blockages.
In addition, it is necessary to check whether the pressure relief valve is working properly. If the valve in the pressure circuit gets stuck in the return position due to contamination, it may cause a malfunction, allowing the pressure oil to flow directly back to the tank. Other potential causes include loose pipeline connections, severe internal valve leaks, or damaged seals of hydraulic cylinders or motors. To solve these problems, please disassemble and clean the affected valves, check the sealing clearance, and replace any worn or damaged sealing components.
