Mountain Bike Reviews Forum banner
1 - 20 of 21 Posts

·
Registered
Joined
·
643 Posts
Discussion Starter · #1 · (Edited)
I have a pair of Shimano BR M555 hydro disc brakes that squeal whenever its wet. Its horrible - and the front is especially bad. Its that type of squeal that goes up through the fork and bars and then into the depths of my soul... seriously though i can feel my bars vibrate when it happens!

It seems like it doesn't matter what i do: once a little water builds up between the pads, no amount of dragging the brake (heat up rotor, drag dirt/water out, etc) ever gets rid of it.

Oddly enough, the brakes are downright awesome when its dry. No rubbing or squealing, great modulation and adequate power. But the noise in the wet is a dealbreaker, since it is usually rainy where i ride.

I have a shimano 160mm and hayes 160mm rotor in the back. both are IS calipers with shims, on a steel fork and aluminum frame that have both been faced.

What Do?
 

·
Registered
Joined
·
1,236 Posts
can we have a thread dedicated and stickied about why some brakes will squeek in the wet? why do i feel like it gets asked a thousand times?
 

·
Registered
Joined
·
643 Posts
Discussion Starter · #4 ·
so thats it? im just stuck with it? my last ride was about two hours of mind numbing howling...
 

·
Registered
Joined
·
1,236 Posts
pretty much... are you really using your brakes that much or are they doing it without the brake applied?
some rotors hold water worse than others, the round holes in shimano rotors could be holding water. the hayes might also be doing it. I personally don't mind too much if it's not a constant thing and the brakes still work just fine. i actually think it can sound cool :D
 

·
Registered
Joined
·
464 Posts
I reckon that the pads are contaminated.

What pads are you running in the brake?
If you are running resin pads (M02), swap to the metal ones (M01). Where I ride (with M775 brakes) is mainly wet year round, I couldn't use the resin pads as they wouldn't last in those conditions and the braking is seriously poor.

If you are already using metal pads, then clean the rotors with alcohol and flame the pads over a gas burner and watch for any smoke/contaminant burning off the pads. Let them get good and hot. You can cool them in water to help with re-fitting.

I run the metal pads in my XT brakes and they are silent in all conditions. The only time they make noise is when there is some contaminant after getting on them and I use the above method to sort that out with great results.

You can try flaming the resin pads but they may not take too kindly to the high temps and you may destroy them.
 

·
RIP Friendgirl
Joined
·
462 Posts
Hayes V Cut Rotors

I've found my 555 brakes to work the best with Hayes V Cuts & M01 pads. They will still make noise now & then, but are surprisingly good for such a cheap hydro.
 

·
Registered
Joined
·
411 Posts
DGB said:
I reckon that the pads are contaminated.
I reckon not. From the Disc FAQ at the top.
The brake will squeal when wet.
My brand new Hope's squeal when wet, my Elixir 5's squealed when wet, and the pads were not contaminated on either. I guess you can consider yourself lucky your's don't squeal when wet.
 

·
Registered
Joined
·
464 Posts
It's not just me and my set of XTs, there are plenty of other people I ride with whose brakes don't squeal in the wet and these include Stroker Trails, Louise BATs, Juicy 5s/7s.

You need to bed the pads in properly too to avoid noise and to increase longevity.
 

·
Never trust a fart
Joined
·
4,543 Posts
DGB, The OP stated that the noise ONLY HAPPENS WHEN WET. If it was a pad seating issue, then it would happen all the time.

My BB7's squeal when they get wet. My Juicy 7's squealed when wet. Shimanos squealed when wet. Most brakes will make noise when wet.
 

·
Registered
Joined
·
643 Posts
Discussion Starter · #11 ·
frdfandc said:
DGB, The OP stated that the noise ONLY HAPPENS WHEN WET. If it was a pad seating issue, then it would happen all the time.

My BB7's squeal when they get wet. My Juicy 7's squealed when wet. Shimanos squealed when wet. Most brakes will make noise when wet.
they are unbearably loud and annoying. Happens with both light and hard braking. I am using metal pads, only ones i've ever used.
 

·
Registered
Joined
·
464 Posts
frdfandc said:
DGB, The OP stated that the noise ONLY HAPPENS WHEN WET. If it was a pad seating issue, then it would happen all the time.
I never mentioned anything about a pad seating issue. :confused:

Slurry said:
they are unbearably loud and annoying. Happens with both light and hard braking. I am using metal pads, only ones i've ever used.
Flame the pads and clean the rotors with IPA, see if that makes a difference. IME it will help.

What rotors are you using?

From my friends and my own experience, our different brand brakes (Shimano included) don't make noise in the wet. I can't put that down to just luck.
 

·
Registered
Joined
·
411 Posts
DGB said:
From my friends and my own experience, our different brand brakes (Shimano included) don't make noise in the wet. I can't put that down to just luck.
From all the experience on this board when one of these threads pop up and the number of people that come out and say that is normal for disc brakes to make noise when wet. I would put it down to just luck.

Let me put it this way if it was contaminated pads you would be losing braking power along with the noise. And the noise wouldn't go away once you get the water off your rotors.
 

·
Registered
Joined
·
464 Posts
It may be "normal" that there may be some amount of noise sometimes but not the amount that the OP is talking about.
I'm just giving my own knowledge and experience in wet conditions to help out. It won't take that long to perform what I've suggested and it may solve his problem.
If you have something else to suggest to help him out, fire away....
 

·
Registered
Joined
·
78 Posts
tried different pads?

I had HORRID brake squeel with my shimanos (M665) and only on the front. Mine did it when they were dry as well. I found that running the organic pads up front fixed the issue. They don't last as long, so you can actually use 1 organic pad and 1 metal, then switch when then the organic wears out if this is an issue.

I'd try this first, you could also try sanding the rotors and pads to rough them up, as well as cleaning them with IPA or clean streak.

Found it odd that only the front did this, pretty sure it was a harmonic issue and had a lot to do with the lack of stiffness up front compared to the rear. Hope you can get it fixed!
 

·
Off the back...
Joined
·
2,304 Posts
I had 775s with Shimano metallic pads for a while. The only time they didn't squeal was when they were wet. It was horrible on extended descents. I switched to Fibrax metal pads and the noise was gone, wet or dry. My SLX brakes have the organic pads, and they squeal a little when wet, but not much.
 

·
Never trust a fart
Joined
·
4,543 Posts
DGB, If you didn't mention a pad seating issue, then what is this????

DGB said:
You need to bed the pads in properly too to avoid noise and to increase longevity.
Pad seating/bed the pads. Its the same thing.
 

·
Registered
Joined
·
643 Posts
Discussion Starter · #18 ·
pinkrobe said:
I had 775s with Shimano metallic pads for a while. The only time they didn't squeal was when they were wet. It was horrible on extended descents. I switched to Fibrax metal pads and the noise was gone, wet or dry. My SLX brakes have the organic pads, and they squeal a little when wet, but not much.
Wow, thats actually great news. I picked up four sets of those that a shop was clearing out, but I have yet to try them. They were $2 a set, so i had to get them.
 

·
Registered
Joined
·
464 Posts
Pad seating and bedding in are not the same thing in my book - lost in a lack of translation.

That's a good price on those spare pads. Good luck!
 

·
Old man on a bike
Joined
·
12,395 Posts
frdfandc said:
Pad seating/bed the pads. Its the same thing.
I dunno about that. While I've seen terms like bedding in or burning in or meshing or burnishing or mating to describe the pad/disc break-in process, to me seating is more about how the pad sits in the caliper...

There really should be a sticky at the top of the forum generally addressing brake noise; I know some it's covered in the FAQ but I think most people don't even see the FAQ. There are so many reasons a brake can make noise. What I usually don't get is the expectation that they shouldn't make noise at all, ever...that's definitely not been my experience even with rim brakes. FWIW wet brakes making more noise is fairly normal in my experience.
 
1 - 20 of 21 Posts
Top