XT brake problem

JGTR

Hi all, got a problem with my XT disc brakes, brakes are approx year old.

Removed front caliper for cleaning and accidentally pulled from brake lever in once (maybe twice, wasn't thinking :roll: ). Put it back on and pulled lever then tightened bolts. Span wheel, horrible noise, disc is not central and catching caliper. One piston appears to be out further than the other hence caliper not central. Removed pads and reset Pistons, still the same. Only way I can get it to work is to visually align the caliper centrally over the disc.

Do these brakes have problems with sticky pistons? Is this a common problem? Wil the Pistons eventually sort themselves out??

Thanks

Jay

codfather

Pulling the lever and fastening the bolts with the pads firmly on the rotor is the quick fix way of aligning calipers. It's fine if it works, but often won't. Aligning by eye is the best way of getting it central.

Try removing the caliper from fork/frame, pads from caliper and set aside. Carefully apply some brake cleaner or degreaser to the pistons, then use a paper towel or ideally cotton buds to clean around them. Pump the lever a little (but not too much) to free things up and dislodge contaminants.
Once that's done reset the pistons and align by eye

JGTR

Thanks, puts my mind at rest, all seems to be working fine now, I'll try and clean it soon.

Rightarmbad

Shimano specifically warns against using brake cleaner as it will react with their seals.
If the pads are sticking, squeeze the lever to push them out a ways, use a cotton bud with some isopropyl alcohol to clean the sides of the pistons, push them back in and check they both move freely.
If not then push them back out and again using a cotton bud, smear a little shimano fluid on the sides of the piston.
Push them back in and test again. repeat if necessary.
Clean leftover traces of fluid from pistons and caliper with isopropyl alcohol, refit pads, align and go ride.