Noise when pressing clutch pedal.

Hi all. Every now and again when I use my car the clutch pedal makes a strange clunky noise for the first 2 or 3 presses then it gradually disappears and won't do it for a while. Any ideas what it could be. I know you can't really hear it brilliantly on this video but it makes a metallic spring noise to go with the clunk. It's done it for years. I did have the clutch and flywheel changed last year but it did it before the change and continues to do it.