Double-acting hydraulic actuators are commonly used in various industries. Their failures may result from many factors, both external and internal. External factors, such as weather conditions, may cause corrosion of the external parts of the hydraulic actuator. In turn, internal factors, e.g. leaks, may deteriorate the operating parameters of the entire hydraulic system. Leaks result from the wear of sealing elements may lead to the extension of the failure range to other parts of the actuator. Due to the trend of limiting the use of galvanic chromium, which is harmful to health and the environment, there is a need to replace this type of modification with others. The paper discusses the issue of seal wear after a certain number of working cycles of a double-acting hydraulic actuator. The aim of the conducted research was to demonstrate the impact of surface modifications of actuator elements on seal wear. Long-term tests were performed on standard actuators and those with various modifications to the piston rod and piston surface, such as: vacuum nitriding, gas nitrosulphurization and DLC (hydrogenated amorphous carbon with tungsten carbide nano-crystallites nc-WC/a-C:H). The designed stand provided all the tested actuators with the same working conditions and loads. The working seals were compared with their brand-new counterparts. Microscopic tests showed that the use of nitrosulphurization provided the lowest wear of the surface of standard seals used in hydraulic actuators.