Determining and Fixing Hydraulic Cylinder Leakage

Hydraulic cylinder leakageoccurs when the piston seal of the Hydraulic Cylinder leaks, and the entire leakage process occurs inside the hydraulic cylinder. This is called hydraulic cylinder leakage. So, how can we determine if a hydraulic cylinder is leaking during use?

1. Methods for Determining Whether a Hydraulic Cylinder is Leaking

• At the production site, we can use hearing, smelling, and observing to observe whether the hydraulic cylinder can move, whether the movement is slow, whether we can sense changes in oil temperature, vibration, or noise. Based on our own experience, we can determine whether the hydraulic cylinder has an internal leak.
• Another common method is to extend the hydraulic cylinder to its full position, ensuring that the cylinder is free of any load and will not retract. Turn off the machine, remove the oil pipe from the rod chamber, and press the switch to extend the cylinder to increase pressure. If oil flows from the oil port of the rod chamber, the hydraulic cylinder has an internal leak. Otherwise, there is no internal leak.
• The third method is to drain the oil and unload the load. Remove the main return oil pipe from the oil pipe joint at the upper oil hole of the hydraulic cylinder and connect it to an empty oil pan. Raise the Lifting Cylinder piston to its highest point, drain the hydraulic oil from the upper chamber of the piston, and then cycle the multi-way reversing valve back and forth several times. Since the upper chamber is not replenished with pressurized oil due to the removal of the main return oil pipe, refill the lower chamber of the piston and raise the piston to its highest point. A large amount of hydraulic oil will be discharged from the upper chamber, indicating internal leakage from the lifting cylinder to the upper and lower chambers of the piston.
• Other symptoms of internal leakage include air bubbles in the hydraulic oil, unstable hydraulic system operation and creeping, overheating of the hydraulic system, increased tank pressure, and increased pump noise.

2. Solutions for Hydraulic Cylinder Internal Leakage

• When internal leakage occurs, first check all suction pipe joints and connections to find the leak source. Avoid overtightening hose fittings, as this can deform them and increase leakage. Use the tightening torque specified by the equipment manufacturer. This ensures a reliable seal and prevents distortion of the fittings and seals, which could damage the seal surfaces.
• Leaks can also be caused by wear and tear of components in the hydraulic system. Over time, internal leaks become more noticeable. Minor internal leaks may not be noticeable, but as they increase, system overheating can become a problem. When this occurs, other system components will begin to fail. Therefore, timely inspection, repair, and replacement are essential to ensure proper operation.

Summary

Hydraulic cylinder leakage can significantly impact system performance, leading to inefficiency, overheating, and component failure. Common detection methods include sensory checks for abnormal movement or noise, pressure testing by isolating the rod-side port, and monitoring oil discharge after cycling the cylinder. Leaks often result from worn seals or loose fittings, which should be tightened to manufacturer specifications without over-tightening. Regular maintenance and timely seal replacement are essential to prevent further damage and ensure reliable hydraulic system operation. Addressing leaks promptly helps maintain efficiency and prolongs equipment lifespan.