What are the reasons why the lift truck cannot rise halfway?

[KadenDella]

The reasons why the lift truck cannot rise halfway: 1. Severe wear between the valve stem and valve body: The directional control valve of the lift truck has three grooves on the lifting tilt rod. These grooves, combined with the oil passages, can connect or cut off the oil flow, modifying the task setting of the equipment. A well-functioning distribution valve has a very small gap between the valve stem and valve body, resulting in minimal oil leakage. 2. Severe wear of the cone valve: The main function of the cone valve is to prevent the backflow of oil. When the cone valve is severely worn, the oil passage may not close tightly, causing hydraulic oil to flow back. This can lead to rusting of the equipment. During routine maintenance, it is important to grind and replace the components to avoid hydraulic oil backflow. 3. Aging of the sealing ring: The sealing between the valve stem and valve body relies on the sealing ring. When the sealing ring ages, hydraulic oil may leak out along the valve stem under system pressure, leading to oil leakage in the valve body. In such cases, the sealing ring should be replaced promptly.

[DeAlana]

I often use car lifts for repairs, and this issue is too common. If it gets stuck halfway up, it's mostly due to low or aged hydraulic oil leaking, causing insufficient pressure; it could also be that the hydraulic pump itself is faulty—if the rotation sounds off, that might be the problem. Another reason could be electrical issues, like loose wire connections or a malfunctioning control switch, where unstable current interrupts the lifting. The safety lock mechanism might also trigger to prevent overloaded lifting. If there's a clicking sound during lifting, it could be mechanical parts jamming or bearings failing. I recommend regularly topping up hydraulic oil and checking seals—don't wait until you need it to find a problem. Repair shops have professional tools for diagnostics, which are more reliable. During the rainy season, high humidity can cause short circuits, so indoor maintenance is better. Safety first—if the lift is unstable, stop immediately and inspect.

[SabrinaRose]

I've had a car for many years. Last winter, a tire blew out, and when I tried to lift it with the onboard jack, it stopped halfway. I noticed the hydraulic oil reservoir was almost empty. The battery might have been weak too, with insufficient voltage to power the motor. That time, I was by the highway, which was quite dangerous. I quickly released it manually and slowly lowered it, using roadside rocks to prop it up as a temporary fix. From personal experience, older cars are more prone to such issues, like oil line buildup or small stones getting stuck in mechanical parts. I usually keep a portable power bank for emergencies and check the oil level and wire connections before lifting, just a simple wipe-down is enough. Frequent use leads to faster wear and tear, and replacing parts is safer than forcing it. Buying jacks from big brands tends to last longer. Sharing this experience to remind everyone: if you encounter lifting issues in the wild, don't panic—seek professional help for peace of mind.

[LeDamian]

From a mechanical perspective, there are several common failure points when a lifting device stops midway. Hydraulic system issues such as clogged oil passages or accumulated debris slowing down the flow rate; or control valve malfunctions, where the valve fails to open, preventing further lifting. On the electrical side, sensor false signals may mistakenly indicate that the lifting limit has been reached, causing it to stop; or motor overheating may trigger self-protection to cut off power. Safety mechanisms are crucial in design—uneven loads or excessive tilt angles can activate the locking protection system. I've observed that operational errors are common in daily use, such as uneven ground or misaligned lifting points. When troubleshooting, prioritize checking the oil pressure gauge and circuit continuity; replacing components with spares for testing can be efficient. Modern vehicle models are equipped with diagnostic systems that directly read fault codes, making troubleshooting more time-saving.