What Causes the Automatic Descent of the Hydraulic Cylinder?
4 Answers
The reasons for the automatic descent of the hydraulic cylinder are as follows: 1. Piston failure: The movement speed of the hydraulic cylinder is the ratio of the flow input to the cylinder to the effective area of the piston. Due to leakage, the actual flow pushing the piston movement is reduced, thus slowing down the movement speed of the hydraulic cylinder. In this case, the piston should be replaced to ensure a reasonable gap between the piston and the cylinder barrel. If the piston sealing ring is damaged, it should be replaced with a new one. 2. Directional valve damage: Severe internal leakage in the directional valve, where the sealing relies on the gap between the valve core and the valve hole. Due to various reasons, the gap between the valve core and the valve hole increases, causing the pressure oil from the pump to flow from the high-pressure chamber to the low-pressure chamber through the internal annular gap after entering the directional valve, significantly reducing the flow rate of the oil passing through the directional valve. As a result, the flow entering the hydraulic cylinder is reduced. Therefore, the user needs to replace the directional valve.
I've been repairing cars for over a decade and have seen oil cylinder automatic descent issues many times. The main reasons are aging or damaged seals causing oil leakage through gaps, which prevents pressure maintenance. Stuck or improperly closed valves are also common occurrences - when dust or debris gets inside and blocks them, oil flows back. Another factor is air bubbles entering the system, causing hydraulic failure. When discovering this problem, always check oil levels first and look for external oil stains; if occurring on a jack, unstable positioning may cause the vehicle body to drop and injure people. I recommend immediate cessation of use and professional inspection for seal replacement. Regular environmental cleaning and periodic oil changes can reduce failures. Safety first - never handle this issue carelessly.
A few days ago, I also encountered the issue of the oil cylinder suddenly descending on its own, which was really alarming. It's probably due to the seal ring failing or insufficient oil, as I haven't had time for maintenance despite frequent use. I tried adding some hydraulic oil, but it didn't help. Then I discovered that the valve was rusted and couldn't open, and cleaning it didn't solve the problem. Safety should never be compromised, especially when carrying heavy loads, as it's prone to accidents. So, I'd like to remind everyone: if you notice any abnormalities, don't force operation. Instead, have a technician check the source of the problem as soon as possible. After each use, simply wipe off any oil stains to prevent dust accumulation, which can affect the lifespan.
Automatic dropping of the oil cylinder is a dangerous signal that can easily lead to accidents. Common causes include internal oil leakage resulting in insufficient pressure, or air entering the system causing a loss of thrust. If used on lifting equipment, sudden dropping may injure people or damage objects. I strongly recommend stopping use immediately, checking for signs of oil leakage, and ensuring a safe operating environment. For prevention, conduct regular system inspections and oil changes; addressing issues early is better than dealing with consequences after an incident. Safety comes above all else—never overlook it.
