A reseal and a rebuild are two different depths of hydraulic cylinder repair. A cylinder reseal renews only the sealing elements inside the cylinder, including the piston seal, rod seal, wiper, wear rings, and static O-rings. During this process, the barrel, rod, piston and end cap are cleaned, inspected and refitted as they are. Conversely, a cylinder rebuild is a complete overhaul. The process involves stripping the cylinder to its bare components, honing the bore back to a true finish, rechroming or replacing the rod, renewing the worn bushes and glands and changing the seals in this rebuilding process. Choosing correctly is the difference between a cylinder that runs for another five years and one that leaks again within weeks.