Originally Posted by
mattkime
>Pads are porous, if they're contaminated more than very slightly you cannot clean them.
Seems like a recipe for throwing away a lot of pads if you're having a problem.
I must have some rotten luck with my front brake. I can't imagine many people have this into to disc brakes, nobody would find them worth the hassle.
It can be, but really most contamination is from mistakes during handling or maintenance. If there is leaking from the pistons the only solution is to replace the caliper (for Shimano at least, also warrantee-able if in warrantee period). As a working mechanic, it's definitely 90% people accidentally getting oils on the pads. I've never had a contaminated pad on a personal bike. I have seen legitimate issues with calipers that have caused contamination however. I've also totally made mistakes in the shop and contaminated a customer's brakes--free fresh pads and a nice clean rotor for them and a lot or wasted time and a likely unprofitable work ticket for us. Then again, I've bled many hundreds of brakes, has happened a couple times.