Recent generation XT brakes, new XT resin pads and XT (standard) rotors (180 F, 160 R). One night this week I was riding in drizzly muddy conditions. Brakes felt juddery and did not stop squealing very loudly all through the ride. A riding buddy commented on how much steam was coming off the back rotor. Now in dry conditions, fine.

Rotors are about four years old. Does there come a point when there’s a need to replace rotors because they’ve had too much use? I’m thinking this can be the only issue. The squealing was above normal wet weather levels.

its probably the obvious one, but are the pads or rotors contaminated? Any oil on them? Give the rotor a wipe down with disk cleaner (I use white board cleaner).
Ive found that shimano resin pads can squeal a little, but only at low speed (i.e. coming to a stop). But my metal pads never make a sound.

ALso, did you wear/brake in the pads? They can sometimes end up with a glaze on them if not worn in propertly. Im not sure if that could cause a squeal.?

I’m amazed you’ve got four years out of a pair of XT rotors.
They seem to last me around 18 months before they become to thin to use.

I think that’s the problem Stu, the rotors might have had it. I’ll get some disk cleaner and see if that helps, but will probably buy some new rotors. Any recommendations for ones that last?

Any recommendations for ones that last?

XT if yours have lasted 4 years!