Brought my mountain bike in for hydraulic disc brake repairs (I thought an independant shop would give me the best quality service) Was told it was impossible to repair the leaking caliper and that the entire back brake system including disc rotor needed to be replaced at a cost of at least £110 parts plus labour. (Disc apparently needed to be replaced as it had been contaminated with brake fluid - it could not be cleaned) Took bike to local Halfords for a second opinion. Halfords repaired the leaking caliper with new seals for £35 - all in. Well done Halfords !