Top 10 Reasons For Hydraulic Cylinder Failures
Hydraulic cylinders fail for a wide range of reasons from bad specification and misuse to just plain old age. Here are the top 10 reason failure and how to go about the hydraulic cylinder repair.
1. Regular seal leakage
This can be caused for a number of reasons the most common of which on new cylinders is incorrect fitting of the seals, however incorrect metalwork clearances may also cause early stage failure. Another physical reason for this failure once the device is in use is corroding, or marking of the seal grooves. The oil itself may also be the cause either because it is contaminated, or else because air has been trapped.
2. Piston rod scored
Scoring of the piston rod is often caused by oil contamination, but this may also be contamination of the gland bearing. If not caught in time then the gland bearing may have failed completely.
3. Cylinder bore scored
Scoring of the cylinder bore can also be caused by contamination of the oil, which may in turn be a sign of piston head bearing failure.
4. Barrel internally corroded
The most likely cause of a barrel being internally corroded is water in the oil.
5. Piston rod pitting
Pretty much the only cause for piston rod pitting is corrosion. This may also be a sign that the cylinder is either wrongly specified or perhaps being used in an environment for which it was not designed.
6. Leaking from around the gland outer diameter
Leaking from around the gland outer diameter can be caused by o-ring failure, or by having a cracked gland, either which in turn could have been caused by poor clearances.
7. Bent piston rod
A bent piston rod may be a sign that the hydraulic cylinder is a being overloaded. This may be because the cylinder and associated piston are working outside of their specification - overloaded in other words. It can also be caused by an outside (sideways) impact of some kind - for example a collision.
8. Split weld on base and ports
A split weld on the base and ports may be caused at the original manufacture (or recent repair) by a poor weld failing. It may also be caused by shock loading - or a sudden impact to full pressure (or beyond).
9. Eye bearing broken
A broken eye bearing is usually caused by the cylinder working on a load above its specification, or else by a shock loading - or a sudden impact to full pressure (or beyond).
10. Rod worn on one side
A rod worn on one side is a sign of a sideways movement of some kind either from a lack of bearing support (perhaps from bearing failure), or else too much side load which can be a result of misalignment or misuse. The rod itself may actually be under specified for the load and so the use of the cylinder should be checked to make sure it is being used within specification.
The above list is not exhaustive of course, but these are the most common failures. Often a hydraulic cylinder repair is an opportunity to review working practices, or raise the specification of the cylinder. This means that not only is the problem fixed but preventive measure applied to reduce the possibility of future recurrence.