I just had my rear discs and pads replaced (2015 Golf). Everything seems fine, but if I'm backing up and press the brakes, there will be a "clunk" on one or both sides; when I then drive forward and press the brakes there will be another "clunk". It isn't loud, but it's clearly present.
If I don't switch directions and brake it won't happen again; only when I brake in reverse (and then the next time I brake going forwards). This didn't happen before the replacement, and I haven't heard it while driving other cars.
It sounds like the pads are sliding to one side of the calipers when I brake in one direction, and then the other side when I brake in the other direction. Is this right? Should I take it back to the shop and complain, or is this completely harmless? I don't care (much) about the noise; I just wonder if it's causing wear, or an indication of some other problem.
(I'm guessing this post was talking about the same problem, but it wasn't explained clearly and there were no answers.)