Do I need new pads or just a fresh bleed?
I have Shimano XT brakes with about 600-800 miles on them. It's starting to take a LOT of pressure to get my rear tire to lock up and the front feels a bit less grabby lately too. Not that I need it to, but it feels like a measure of something needing maintenance.
I pulled the pads a few weeks ago and they look almost new. I used rubber gloves to make sure I did not contaminate the pads. Do I just need to bleed the brakes? I bought a bleed kit a while ago because I knew I would use it eventually and needed to hit a minimum dollar amount for free shipping. I got beefier tires recently but can't remember if it got harder to lock up at that moment or not...
Do pads ever go bad other than contamination? Is needing a bleed other than at time of pad replacement a symptom of a leak or something? I know with cars you typically bleed the brakes every 3-4 years so having to do it when the bike is 6 months old seems odd to me with the amount of miles it has.
Could need a bleed.
Could need to clean rotors and reset pads + caliper pistons.
Check to see if you have air in the lines by turning the bike upside down for a few minutes then flipping it right side up and squeezing the brake levers. If the levers feel softer than usual or go to the handlebar immediately, you need a bleed.
If you notice no difference in the lever pull, do the following:
Clean your rotors with a light scuffing of sandpaper and a wipe down with iso alcohol.
Re-bed the pads
If that doesn't work, reset caliper pistons and align calipers to rotor.
If that doesn't work, bleed the brakes, replace the pads, clean the rotors and start over.
I think Norman hit it correctly with cleaning the pads/rotors. Sounds like they are glazed. Pull the pads and rotors. Hit them with some 220 grit sandpaper, then clean the rotors with denatured alcohol.
What circumstances glaze rotors/pads? Is the sandpaper/alcohol method a common activity for you guys?
Also what's the difference between iso and denatured alcohol?
Not common but helpful.
Originally Posted by Alias530
Glazing occurs from repeated slowing on steep downhills.
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