Just replaced the seals on my AP Racing calipers , ive suffered from some brake issues that im hoping ive now cured , i'll tell you tomorrow after testing at Brands Hatch . The shit that came out of the calipers after i pulled the pistons out would make you cry , these have been bled on numerous occasions and only run on Motul Racing fluid yet still they were full of water and shredded bits of seal ! Sod using these on the road , if you dont have dust seals in your calipers , get real familiar with this job !!