How to Repair a Manual Hydraulic Forklift That Won't Lift?
2 Answers
Manual hydraulic forklifts may fail to lift due to the following reasons and corresponding repair methods: 1. Excessive wear gap between the valve stem and valve body: The multi-way directional control valve's lifting lever has three grooves. These grooves, in conjunction with the oil circuit assembly, can connect or disconnect the oil circuit, modifying task execution. The gap between the distribution valve stem and valve body is very small, resulting in minimal oil leakage. Therefore, the hydraulic cylinder's descent or tilt is minimal and does not affect task performance. However, when the wear gap becomes too large, under the pressure of the task pump, hydraulic oil may form in the task pipeline connected to the return oil pipe or spillway, automatically returning to the oil tank. If wear occurs, due to prolonged use of the distribution valve or unclean oil, the wear between the valve stem and valve body will accelerate, damaging the sealing surface of the joint and causing oil leakage. During repair, if the valve stem is lightly worn, chrome plating and polishing can be applied; if the valve stem is severely worn, replacement is necessary. 2. Wear of the cone valve: The cone valve prevents oil backflow. If the cone valve is worn and the oil passage does not close tightly, hydraulic oil may backflow, rendering the system ineffective. During repair, grinding or replacement should be performed to eliminate backflow.
I use this thing often, if the manual hydraulic pallet jack won't lift, it's mostly a hydraulic oil issue. First check the oil level - if it's low, top up with the appropriate hydraulic oil. With insufficient oil, there won't be enough pressure to lift. If the oil is full, check for any leaks, like at the cylinder or connections - small leaks can lead to big accidents. Worn or damaged seals are very common - just replace them. Sometimes air gets into the system - pump the handle up and down a few times to bleed it. Overloading is another common reason - the jack has a rated capacity, don't force it. The pump might be stuck or the relief valve failed, requiring disassembly for cleaning or part replacement. Safety first - wear gloves during repairs, use proper tools, or send for professional repair if needed. Regular maintenance like cleaning and oil inspection can prevent most issues.
