There are a number of reason why hydraulic cylinders fail ranging from misuse to bad specification to old age. Here are the most typical reasons why they fail: Seal leakage The most common reason for an issue here is because the seals do not fit correctly. Another problem can be corrosion or abrasion of the seal grooves. If the oil is possibly contaminated or there is trapped oil, this should also be considered. Piston rod scored Oil contamination can cause a lot of issues, one of them being the scoring of the piston rod. However, keep an eye out in case there is contamination of the gland bearing as this can lead to gland bearing failure if not caught in time. Cylinder bore scored Contamination of oil can also wreak havoc by being the cause of scoring the cylinder bore. This can even turn out to be piston head bearing failure. Flushing of the system can help with this. Barrel internally corroded Water in the oil is usually the cause of the barrel suffering from internal corrosion. Start with changing the oil and there may be a need to disassemble and recoat. Piston rod pitting Corrosion can also cause piston rod pitting. It may also be a sign that there is a wrong specification of the cylinder or perhaps the environment in which it’s being used is not what it was designed for. Bent piston rod This will quite often occur when there is an overloading of the hydraulic cylinder. This could be due to the cylinder and piston being used in a way that is not in alignment with their specification. It may also be caused due to a sideways impact from outside, perhaps from a collision. Generally speaking, most engineers find that contamination and corrosion is at the heart of the majority of hydraulic cylinder failures. This is why it’s essential to protect your hydraulic system from moisture and oil contamination.