A seal assembly includes a piston and a seal. The piston includes a first radial piston wall, a second radial piston wall extending radially further than the first radial piston wall, a groove formed between the first radial piston wall and the second radial piston wall, and a bypass line extending at least partially around the groove. The seal disposed in the groove. The seal includes a first sealing lip extending radially outward beyond the second radial piston wall and a second sealing lip. The second sealing lip is sealed against the first radial piston wall to seal an entry space when acted on by a pressure below a predetermined pressure limit pG, and pivotable radially inward to open the entry space when acted on by a pressure above the predetermined pressure limit pG.