All hydraulic seals put into use have a day when they're going to fail, but that doesn't mean you have to bring about that moment any sooner than absolutely necessary. You also don't want to have to replace any more of them than circumstances demand. Given the high pressures and temperatures that hydraulic seals operate under, taking care of them calls for closely watching for specific signs that there is a problem. It's also a good idea to know when it's time to give it up and replace them.
Sign 1: Elasticity is Gone
When hydraulic seals are beginning to experience complete deterioration, their elasticity will go away. The seals will feel stiffer and less rubbery than expected, and eventually, they will dry out and crack.
This occurs in two common situations. First, the fluids within the system are operating at too high of temperatures. You should do everything possible to reduce those temps. Second, the seal itself may be exposed too much UV radiation, usually from the sun, or too much ozone, typically from the working environment.
If ozone is the issue, try ventilating the work area better. If the sun is the problem, attempt to limit outdoor daytime exposure as much as possible. Also, make sure that spare seals aren't being stored in places where they're exposed to sunlight or ozone.
Sign 2: Fracturing
When there's excess back pressure in a system, you'll begin to see fracturing of the hydraulic seals. This can occur for a wide range of reasons, including dieseling, internal explosions and low start-up temperatures. System fluids may also experience breakdown. Fracturing is often a sign of other problems in a system, so you may actually want to take the unit in question out of service and give it a thorough inspection rather than just treating or replacing the seals.
Sign 3: Extrusion
Surfaces that should be completely flush, such as between the seal and the piston rod, show gaps. This is usually the product of the rod moving in a non-uniform manner due to wear in the rings or the bearings. The seal will have to be replaced, but you should also break the component down for an inspection.
Sign 4: Grooves
If a visible groove appears in the seal, something is in the fluid. While it may be dirt, the most common source of trouble is air bubbles. Bleed or flush the system.
When your hydraulic seals need to be replaced, reach out to a local supplier.