Brake Squeal/Noise from Trek Session+Saint

If you have resin pads already installed switching to one metallack and one resin won't fix your issue. Resin pads are quieter than metal, which is why people running metal pads would swap in one resin if they had loud brakes. The idea was to still have some of the power//grab of metal pads, but with the quieter traits of resin. In your case, you already have the "quietest" setup.

Did you swap rotors and pads at the same time? If not, if either were contaminated they'll just cross contaminate the replacement.

If you're positive your pads//rotors aren't contaminated (replaced both at the same time), try the following:

Use compressed air to blow out your calipers. Sometimes the noise is just dust. If that doesn't fix it, check for leaking pistons.

Pull your pads and inspect the back of the pad and inside the caliper. You're looking for mineral oil that might be leaking from the pistons contaminating your new pads//rotors. This probably isn't your issue though, you'd lose power fast if this was the case, just worth checking. Reset your pistons and continue with cleaning and resurfacing//adjusting laid out below.

I believe the ICE Tech pads come with the bottom edge of the pad already rounded, but if not, pull your pads and sand the lower edge of the pad to round the square edge down. Do this to the leading edge as well (the edge of the pad facing the back of your bike). Sand the actual pad surface down a bit too just to get some fresh pad material exposed. Clean your rotors with denatured alcohol (Home Depot sells it). Reset your caliper alignment properly. You can do the "squeeze your lever" method to center your rotor. If one piston extends further than the other that could also be the issue. Instructions how to try and fix this below. If the pistons extend equally and the rotor is centered in the caliper, snug up the caliper bolts slowly so they don't shift the caliper position. Check to make sure both pads contact the rotor at the same time. Bed in the pads properly and see if the noise returns.

If one piston is moving before the other, with the pads out and wheels off, SLOWLY squeeze the brake lever to extend the pistons. Be very careful when doing this, if you push the pistons out too far they'll pop out completely and you'll have to completely re-bleed the line and possibly damage the seals or the pistons themselves. When the pistons push out a centimeter or so, hit them with the alcohol and reset them carefully with either a bleed block or box wrench (don't chip the ceramic pistons) and repeat the process a few times without the alcohol step. This helps lube the piston//seals and cleans out any grit that can find its way in there. If the pistons start moving equally, clean out the caliper with the pistons pushed in so you don't get mineral oil on the pads//rotor, and reinstall everything and center the caliper.

If you do all this and they still howl, I don't know what to say. Some brakes just howl, sucks but happens often.

my session did that years ago. I swapped pads, rotors, rotor size, brake adapters everything I could think of.


they always howled. My suggestion is to try braking less.

Go to your local Trek dealer and ask them to order PN W438845
It's one of those 'harmonic dampers' that Cuddly Toast mentioned above, but its only available for 160mm mount so you'll have to add some spacers to get it up to 180/203mm

Gotta love that spacer science. Good find. It used to be fun in the first days of the Boxxer.

Early devinci split pivot Wilsons had a rear brake squealing problem. It had something to do with the split pivot rear dropout vibrating. They fixed the problem but I'm thinking trek might have a similar issue due to their split pivot design. Just theorizing....