Bit of a strange one here folks… wondering if anyone has come across this before.

I’ve changed the hose on my rear XTR Trail M988 brake to a Goodridge hose and done a bleed in my cellar, where the ambient temperature is about 10 degrees. Brake operates as normal—firm after about 10mm of lever travel. But.. as soon as I bring the bike somewhere warmer, like upstairs or in the car, the lever pulls to the bar and doesn’t return fully. Once I’ve got the bike out on the trail, after about 5 minutes (once it’s cool again), normal performance returns.

Obviously this isn’t too much of a problem at the moment (it’s cold outside), but I’d imagine that it’ll become an issue in the spring with warmer ambient temperatures

The front brake (where I’ve also changed the hose) doesn’t have the issue. And in case it seems like it might be a position-related issue, I the problem exists both when upright in the house and on its side in the car. The hoses seem fine—there doesn’t seem to be any leaking fluid.

Any thoughts? Voodoo magic? Witchcraft? Global economic meltdown?

That is not much of a temp change. I would suspect sticky pistons stopping it returning. Push them out a bit and clean / lube them. Then just bleed again to ensure no air bubbles moving about.

It that dosent work its Voodoo.

Bleed again but make sure the pistons are pushed fully back.