Broken hydraulic cylinders can often reveal valuable information about how they’ve been used—just by examining the type of damage. In this blog post, we’ll run through the top 5 most common causes of cylinder failure. Alongside the root causes, we’ll also share some practical maintenance and usage tips to help extend the life of your cylinders.
1. Impurities/Contaminants inside the cylinder
Contaminants inside a hydraulic cylinder typically start by wearing down the seals, which often leads to internal leakage. A common sign of internal leakage is when the cylinder can’t hold pressure and slowly sinks on its own. If the seals wear out enough, metal surfaces inside the cylinder begin to make contact, causing scratches on the cylinder tube or piston.
In most cases, contaminants enter the cylinder during hose or valve changes. That’s why it’s essential to minimize the time hoses and fittings are left exposed, and to ensure all surfaces are thoroughly cleaned of dust and grit before installation. Oil cleanliness also plays a big role—regularly replacing oil filters helps maintain system hygiene and protects your seals and internal components from premature wear.
2. Cylinders bottoming out
Another common failure type involves cylinders being driven hard against their end caps. Most cylinders include built-in cushioning to slow the piston near full extension or retraction. However, some models—depending on the manufacturer—don’t have this feature and are designed to operate within a limited stroke range. When a cylinder is regularly bottomed out, the machine’s metal components (such as the boom frame and cylinder body) are subjected to significant stress. Over time, this can lead to fatigue-related failures in areas like the piston, guide, end cap, or rod eyes.
To prevent this, the cylinder should be used within its intended stroke range, avoiding repeated impacts at full extension or retraction. Staying within proper operating limits reduces mechanical stress and helps extend the life of both the cylinder and surrounding components.
3. Operator errors during use
“Mistakes happen.” The safest way to keep a machine in perfect condition is to never use it—but that’s not how work gets done. In demanding conditions, machines will inevitably sustain damage that can’t always be avoided. Long hours also increase the chance of errors, so taking regular breaks can help operators stay sharp and focused, reducing the risk of mishandling.
One of the most common operator-related issues is accidental contact between the grab or bucket and the cylinder rod or tube during lifting or rotating. If the same type of damage keeps occurring during a particular task—and across different operators—it’s worth reviewing whether adjustments to the loading technique or workflow could help reduce strain and minimize impact on the cylinders.
4. Exceeding Safety Limits
The structural components of a machine—like the boom and hydraulic cylinders—are designed by the manufacturer to withstand specific force levels. These forces are usually controlled or limited by pressure relief valves. Occasionally, we encounter cylinders from machines where these safety valves have been bypassed, allowing the cylinders to operate under so-called overpressure.
We strongly advise against bypassing a machine’s safety valves. First, it poses a serious safety risk. Second, it significantly reduces the durability of the hydraulic components. When pressure levels are raised beyond design specifications, components like cylinder welds are subjected to extreme stress, increasing the risk of failure.
5. Neglecting to Grease Bearings
As highlighted in our previous blog post, regular greasing of bearings is a critical maintenance task. Proper lubrication helps protect not only the bearings themselves but also the bearing housings—and ultimately, the entire cylinder.
Have you come across any of the issues described above? Or are you wondering what might be causing a recurring fault in your cylinders? If so, get in touch—we’re happy to help you figure it out.
