Truck-mounted cranes have gained significant popularity in the special vehicle market. A considerable number of these cranes are outfitted with hydraulic legs, which play a vital role in distributing the weight of the entire crane and augmenting the vehicle’s carrying capacity. However, during the operational lifespan of truck-mounted cranes, the hydraulic legs may sporadically encounter certain minor malfunctions. So, how should we address these issues?
Let’s explore some common malfunctions of truck-mounted cranes and their corresponding solutions:
When the front vertical legs of the truck-mounted crane are retracted, the horizontal legs are also retracted simultaneously.
Cause of the malfunction: The primary cause for this issue could lie in the improper functioning of the horizontal leg overflow valve of the multi-way valve on the vehicle. This malfunction might be attributed to debris or impurities blocking the valve’s operation or a component within the valve being damaged.
Solution: The first step is to meticulously remove any stuck impurities and ensure a thorough cleaning of the valve. This helps eliminate any obstructions that might be impeding the smooth flow of fluid. In cases where components within the valve are found to be damaged, it is essential to replace them promptly to restore the valve’s proper functionality.
During the operation of the hydraulic legs of the truck-mounted crane, one of the legs extends very slowly.
Cause of the malfunction: There are a couple of potential reasons for this problem. Firstly, the positioning of the multi-way valve might have loosened, thereby losing its ability to effectively control the speed of the hydraulic leg. Secondly, internal leakage within the horizontal cylinder could result in insufficient pressure, consequently reducing the speed of extension.
Solution: To address the potential loose positioning of the multi-way valve, it is necessary to securely fasten it. Another approach involves swapping the vertical and horizontal oil tubes. By observing if the horizontal leg slows down after the swap, it is possible to rule out normal components and identify the faulty one. Thorough inspection of the cylinder is also crucial to determine if there is any internal leakage. In the event of internal leakage, the appropriate course of action would be to replace the seal or the entire cylinder to restore the cylinder’s performance and pressure.
The rear legs of the truck-mounted crane extend and retract slowly, and the pressure is relatively low.
Cause of the malfunction: The root cause of this malfunction typically lies in damage to the internal components of the overflow valve of the multi-way valve, which leads to internal leakage. This leakage results in a loss of pressure and a subsequent slowdown in the extension and retraction of the rear legs.
Solution: To accurately diagnose the problem, a specific inspection process is required. Start by disconnecting the oil tube that leads from the overflow valve of the multi-way valve to the hydraulic oil tank. Position the leg selection handle in the neutral position and then pull the reversing handle. Observe the pressure gauge and wait until the pressure stops increasing. Subsequently, check whether there is oil flowing out of the disconnected oil port of the multi-way valve. If oil is flowing, it indicates that either the overflow valve has internal leakage or the pressure value has been set too low. In the absence of oil flow, it suggests that the oil pump might be damaged.
During the operation of a truck-mounted crane, the hydraulic legs assume an absolutely critical role. Fellow truck owners and operators must remain vigilant and observant regarding the performance of the hydraulic legs during regular use. Swift identification and resolution of any emerging problems are essential to prevent unexpected failures and disruptions at critical moments.
Regular inspections and maintenance of the hydraulic leg system are of paramount importance. This includes checking for leaks, ensuring the proper tightness of connections, and inspecting the condition of seals and valves. By maintaining a proactive approach towards the upkeep of the hydraulic legs, the reliability and safety of the truck-mounted crane‘s operation can be significantly enhanced.
In addition, operators should also be familiar with the normal operating sounds and sensations of the hydraulic legs. Any unusual noises, vibrations, or changes in performance could be early indicators of potential problems. Prompt reporting and addressing of these anomalies can prevent minor issues from escalating into major malfunctions.
In conclusion, a comprehensive understanding of the common malfunctions of the hydraulic legs of truck-mounted cranes and the corresponding effective solutions is essential for ensuring the smooth and safe operation of these vehicles. By adhering to proper maintenance practices and promptly addressing any identified problems, the efficiency and longevity of the hydraulic leg system can be safeguarded, contributing to the overall productivity and reliability of the truck-mounted crane in various applications.
