Hydraulic piston oil seals are designed to prevent hydraulic fluid from leaking out of the piston chamber, while also keeping contaminants from entering the system. These seals are made from durable materials, such as rubber or polyurethane, that can withstand high pressure and temperature levels. By effectively sealing the piston chamber, hydraulic piston oil seals help maintain the proper functioning of the hydraulic system and prevent costly damage or downtime.