Equipment that uses hydraulics to move or lift part of the machine typically use cylinders to do the job. Hydraulic cylinders are not complicated, but if you have one that is failing or leaking, rebuilding it correctly is critical to it working properly.

Leaky Cylinders

The most common reason for a hydraulic cylinder rebuild is because the cylinder is leaking. A leak in the seal will allow hydraulic oil to seep out of the system and can cause the pressure to drop in the cylinder while it is under load. Replacing the seals is not difficult if you have the right tools to tear down and reassemble the cylinder, but installing the new seal correctly is critical, or it can also leak.

Rebuilding Your Cylinders

When you have a cylinder that you want to rebuild, you will need to remove it from the system and take it to a hydraulic machine shop. The machinist can break down the cylinder and check all the parts inside to ensure everything is in good working order, then reassembly the cylinder with a new seal for you. 

The technician or machinist will check the ram that runs through the seal for damage and polish or smooth it out. Rough spots on the shaft can tear the new seal and cause it to leak, so it is critical to remove rough spots. The piston inside the cylinder also has some O rings that need to make a seal between the piston and the body of the cylinder. 

The technician can check and replace the O rings while the cylinder is apart as well. If the pistons seals are worn, oil can get by them and also cause a loss of pressure inside the cylinder. The inside of the body will get checked for damage and rust, and if it needs cleaning and polishing, this is the time to do it. 

Refurbishing the Outside 

While the cylinder is apart, cleaning and painting the outside is a good idea. The new paint, of course, looks nice, but it is there to keep the cylinder from rusting, and putting on a fresh coat is an excellent way to extend the life of the cylinder. 

The parts of the cylinder go into a solvent bath to remove grease and oil, then rinsed off. When they are dry, paint is applied then the cylinder reassembled. The shop will return the cylinder to you, ready to install and put back in service. 

While it might seem easier to buy a new cylinder, there are some older machines that you can not purchase the cylinders for, so rebuilding and reconditioning the ones you have on the machine is your best option.