Quote Originally Posted by deadeye View Post
Don't worry, it's just an impression caused by the pre-load on the spring pressing the piston against the end of the cylinder at rest.
Yep. Not an issue. And, as advised above, for future strips it's always advisable to clean everything thoroughly as even a tiny bit of residual lube can promote dieselling. So, paying extra attention to those little crevices in the seal lip and thoroughly degreasing the cylinder and piston before applying just the right amount of correct lube.