Green welded medium duty hydraulic cylinder

Hydraulic Cylinder Guide: Seal Kits

By Alexa Yates |

Seal kits are used to close gaps between components in hydraulic cylinders. Closing these gaps is essential because seals are responsible for maintaining hydraulic pressure and preventing contaminants in fluid power systems.

If you’re thinking about purchasing a hydraulic cylinder seal kit, you most likely have a few questions. In this article, we’ll outline what you need to know before you make your purchase.

Are Hydraulic Cylinder Seal Kits Universal?

Short answer: no.

There are many types of hydraulic cylinder rebuild kits. Each hydraulic cylinder has unique rod and bore diameters, stroke length, cylinder length, pressure flow requirements, etc. Some of the different types of hydraulic cylinder seal kits include standard, loaded lip, cast-iron piston rings, and fluorocarbon.

One of the best ways to understand what type of kit you need depends on the piston rod’s stroking speed, fluid media, fluid pressure range, and more. You must also be sure that the seals in the kit are the right size.

How to Select the Right Seal Size

Sizing a hydraulic cylinder seal kit is a straightforward process. You need a tape measure and calipers to take measurements. Take your time and be meticulous.

Step 1: Measure the Bore

Determine your cylinder’s bore, which is the interior diameter of the cylinder. Measure bore with a tape measure stretched across the cylinder’s inner barrel.

Step 2: Measure the Piston Rod

The piston rod is normally a chrome-plated, circular piece of hardened steel that’s attached to the piston. Measure its diameter with outside calipers.

Step 3: Determine the Cylinder’s Retracted Length

The retracted length of your cylinder is the distance between the centers of its pin holes when the cylinder is totally closed (retracted). Your tape measure will work best for this step.

Step 4: Measure the Cylinder’s Extended Length

The extended length of a hydraulic cylinder is the distance between its pin holes when the cylinder is completely opened. Again, use your tape measure to obtain this.

Step 5: Calculate Your Cylinder’s Stroke

Simply subtract your cylinder’s retracted length from its extended length. For example, if your retracted length was 12 inches, and your extended length was 34 inches, your stroke will be 22 inches.

Step 6: Perform a Thorough Visual Inspection of Your Hydraulic Cylinder

Carefully evaluate your cylinder’s hose ports, which are where you connect hydraulic lines to deliver fluid into the cylinder. Look for any signs of abnormal wear and tear and order replacement accessories, as necessary.

Have Questions? Contact Yates Industries Today!

Yates Industries has been a leading hydraulic cylinder manufacturer for more than 50 years. We carry a wide range of hydraulic cylinder seal kits, and can help you find the right one for your needs.

When you have your bore, rod, stroke, and other measurements, reach out to us via our fast and easy online contact form, and one of our representatives will get in touch with you shortly.