new front brake pads, even a caveman...

[Igofar]

The thicker side,as you call it, is on the same side as the pistons .

 

[Igofar]

On the later year bikes, the clips can be put in backwards and cause the little tabs to drag on the pistons damaging them.

 

[SMSW]

I'm really surprised that there were so many replies to the original poster and so little emphasis on the correct procedure to flush the system of old brake fluid. Maybe back in '09 SMC's were younger and more tolerant of old brake juice. I too would shun brake cleaner for use on the pistons. That's for the soles of the feet of the original 'caveman' poster.