I have been a little unhappy with the power of the front brakes and decided to replace the pads with my favourites, EBC HH. When I bought this bike last year I gave the pistons a decent clean (and a thorough fluid flush) which helped a lot and I thought I had done a decent job of giving the system a decent once-over.
Turns out, not so much, as I missed a fairly important part of the right calliper, specifically the sliding pins. It took me about 5 minutes to replace the pads in the left calliper including cleaning the pistons, but as soon as I had the right calliper off, it was obvious that the main slide pin was corroded solidly in the alloy hanger.
After trying various methods to free it while still plumbed in, I had to admit defeat and break the banjo fittings loose and pull the calliper right off the bike. Some strategically aimed whacks with a drift got the offending parts apart, and the both pins were dry and crusty and a bit corroded. I cleaned them up, cleaned all the rubbery bits, slathered on some silicone grease and then went through the process of reassembly and bleeding. Should have taken less than 30 minutes but ended up being a good couple of hours.
And at the end of all that I now wonder whether I really needed new pads or if the lacklustre power was mainly due to the lack of calliper movement. Check your calliper slide pins people!