Hydraulic cylinder malfunction is something that everyone operating heavy machinery with a hydraulic system is familiar with. There are many reasons to why a hydraulic cylinder or its components could malfunction. One very common reason why you need hydraulic cylinder service is that the rods in the cylinders are bent. This is not always easy to spot, but it's very important that the hydraulic rods are as straight as possible for you to get as much as possible out of your machines. This fairly simple issue could be caused by many reasons and could also cause a series of serious issues if left unattended.
Many times, bending rods are cause by manufacturing mistakes that are too small to show up when troubleshooting the production but that cause damage when the rods are placed in heavy machinery. The cylinder rods could bend if you are operating with rods that have a too large or too small diameter, as this could cause the rod to not fit properly in the seals or make it jump out of its place without prevalent reason other than operating under normal circumstances.
Another common reason that causes the rods to bend is that you're operating with cylinder rods that are made from insufficient material. Hard chrome rods are usually durable enough to not bend, but could sometimes crack. Also, if the rods haven't been changed in a while, then the chrome could soften and cause the rods to bend.
Another reason that could cause the rods to bend is that the rods are mounted wrong in the cylinder. This could be an existing condition in the cylinder from the start. Therefore, you should make sure to check the mounting of the rods even if they are brand new. Make sure the hydraulic cylinder isn't making any excessive noises while operating and that the rods aren't showing any signs of wear.
Problems if it breaks
Bending rods could cause premature failure of the seal if allowed to operate for a long time without being replaced. A breaking seal could cause leakage in the cylinder, which would waste hydraulic fluid and shorten the life length of the cylinder. In extreme cases, it could just snap, putting your machine to a full stop while you're operating it, which could be very dangerous under the wrong circumstances.
An easy way to prevent dangerous consequences of bent rods is to measure the straightness of the rods every time you are repairing or examining your cylinder. You do this by putting the rod on rollers while measuring the movement on the middle of the rod with a dial gauge.