What Causes Hydraulic Cylinder Oil Leakage?
2 Answers
The causes of hydraulic cylinder leakage are as follows: 1. Internal leakage causes in hydraulic cylinders: Severe wear of the wear-resistant ring on the piston leads to friction between the piston and cylinder liner, eventually damaging the cylinder liner, piston, and seals. Long-term use causes seal failure, and piston seals (mostly U, V, or Y-rings) age. Contaminated hydraulic oil with a large amount of debris entering the cylinder wears out the piston seals, typically due to iron filings or other foreign objects. 2. External leakage causes in hydraulic cylinders: Damage to the seal at the piston rod extension end, often caused by scoring of the piston rod or aging. Damage to the seal between the piston rod extension end and the cylinder liner, usually due to long-term use and aging of the seal, or excessive force during upper cover installation causing seal crushing. Additionally, many domestic hydraulic cylinder manufacturers design unreasonably, often to save costs.
With my years of driving experience, oil cylinder leaks are quite common. The most frequent cause is aging seals—those rubber parts harden and crack over time, allowing oil to slowly seep out. Wear and tear on the cylinder itself is also an issue, as the piston's back-and-forth movement can rub against the cylinder walls, creating scratches that lead to small leaks. If bolts aren't tightened properly or are misaligned during installation, oil can escape through the gaps. Environmental factors like dust buildup or rainwater corrosion can worsen the damage, and cold winters make seals brittle and prone to cracking. During inspections, gently wipe the cylinder clean to identify seepage points. Leaks not only waste resources but also directly impact hydraulic system performance, especially increasing the risk of brake or suspension failure. Timely repairs and part replacements are essential—don’t compromise safety to save money.
