I seem to be going through disc brakes at a horrifying rate, not because they are worn but they seem to be getting contaminated and just stop working. It's happened on several bikes, the only common thing being cleaning them. The only thing I can think of that might be causing it is the brush I generally use to clean my bikes. I use the hope cleaning stuff.

Has anyone had similar problems and managed to save thir brakes? How? I've tried cleaning the rotors with isopropyl alcohol but it's no use!

A brand new pair of XT discs and calipers are about to go in the bin 🙁

Clean with water, if at all!

If you clean the drivetrain with a brush then wipe it all over the brakes then taht might explain a lack of performance but it shouldn't kill the caliper. I never use any cleaning products on my bike – a quick rinse with water to get the worst off and that'll do for me. Have you tried bleeding them, new pads, rotors in the oven etc?

BTW if they're *really* beyond salvation I could do with a spare bleed nipple for an XT caliper I've got in the spares drawer… 😉

sorry, I meant pads not calipers

what's the rotor in the oven trick? I'm wary of replacing the pads without the rotors in case they get contaminated by the rotors again.

I promise I wont clean my bike ever again.

The rotors aren't going to be contaminated if you've cleaned them with isopropyl alcohol surely – they're stainless steel aren't they. If you really think they are still contaminated you could lightly sand them with some fine sandpaper.

You didn't use a greasy cloth to clean them with did you?

I virtually never clean my bike in any way, save for brushing off the dry mud. My XTs are coming up five years of constant (ab)use old and have had no attention at all apart from one re-bleed because I accidentally popped the pistons by knocking the brake lever with the pads out.

Don't clean your bike, or at least not nearly so vigorously!

BTW my LX external bearings are nearly three years old and still going strong – again, no hosepipe!

If you've cleaned the rotors with isopropyl alcohol you should only need to change the pads if you still think you've got a contamination issue.

Wheel off.
Old pads out.
Clean caliper if filthy.
Fit new pads.
Clean rotor with IPA and clean cloth.
Wheel on.
A few start/stops to bed pads in.
A ride to finish bedding them in.

I have ruined rear pads on a couple of occasions by being too energetic whilst cleaning the cassette.

Edit: Usually, I have found, no amount of cleaning will cure contaminated pads.

I've been washing my bike using Turtle Wax car shampoo after every ride for over ten years and I never have problems with my brakes.

TBH throw water on them before you ride and use them hard.

Or just use them hard…

Could it be pads glazing? When you take the pads out, do they look all flat and shiny? If so, they're glazed. I have the same recurring problem, but only on the older-style Shimano XT brakes for some reason. They improve when heated and rapidly cooled, but only for a little while. Think I may go back to organic pads for them.