Squeaky Disk Brakes?

[TXRider60]

This may have been asked in the past... If so, my apologies.
I ride infrequently, and every time I do, the front disks squeal when approaching a stop: If they're noisy when slowing it's not noticeable, and it seems to get a little better after a few miles (15-20 miles). I've had the front brakes rebuilt twice, in the last couple of years (very few miles since either job)...so chances are that it's not a mechanical wear problem. My bike resides "under cover" (carport) but still gathers a lot of dust-- no, let's call it DIRT-- in just a week or two. Could that kind of accumulation result in the squeaking/squealing I'm hearing from the front stoppers?

[Justin B.]

[movedhere] Chit-Chat [move by] Justin B..

[Bob_Roller]

Brake squeal is caused by the pads vibrating in the caliper .

There is an aerosal can product called Permatex Disc Brake Quiet .

It's a blue material you spray on the pad backplate, let it dry then reassemble the brakes .

A few members here said a good coat of automotive rattle can paint will do the same thing .

I noticed that once you get  away from OEM pads the squeal goes away .

I've changed to EBC graphite pads and no squeal in 6 years .

[Justin B.]

I discovered the Permatex stuff probably 25 years ago.  We had a BMW 320i that had front brakes that squalled something fierce unless a good coat of that stuff was on the backs of the pads...

[Mike V]

I'm going to share my feelings on brake squeal again.  Just an opinion but with some positive results, some may agree and some may not.  Bob & Justin I highly respect your opinion and knowledge and am not discounting your advice at all.  I've never been an advocate of anti-squeal products.  They may help reduce the squeal but I see those products as treating the symptom and not the problem.  Hopefully we'll all agree brake squeal is caused by trapped gasses as a result of glazing.  A very thin and hard surface forms on your rotors or pads, or both causing a very high frequency vibration during brake application.  As Bob explained.

The culprit can be too much light braking along with the collection of dirt, grime and normal road debris.  Another cause can be by pads that are not returning completely causing some continuous light contact drag during normal riding and creating a glaze.

Check to make sure your caliper pistons and pads are returning and not contacting the rotor with enough force to create heat.  And that you are not leaking any brake fluid on your brake components causing contamination.

Break the glaze on your rotors and friction pads by abrasive means then clean your rotors well with a non-residue solvent (Acetone or Isopropyl Alcohol works well).  Don't forget to clean the holes on your rotors well.  Yes, it can be a time-consuming project but those holes can hold oil, dirt, grease, etc. that can migrate onto your pads and rotor surface contaminating them. I use a gun bore brush chucked in my electric drill. Twenty minutes tops. Contaminated pads are hard to resurrect - I've never been totally successful with that.

The first thing I would try prior to the glaze breaking - is some aggressive front braking stops.  Find a SAFE place to do 20 or 30 35mph to 0mph aggressive stops.  Don't allow your brakes to overheat.  My dual ATE's also squeal from time to time.  When they do I make some aggressive stops and the squeal goes away.  This also helps burnish the pads, a break-in procedure often overlooked when installing new brake pads.

Or, another option is anti-squeal products.

[davidpdx]

When I got my bike it had a new brake disc and new pads on the front. At low speeds it would make a squeal when not braking. Nice way to announce that you are coming. On the advice of a friend I used the front brakes hard when in a safe spot a number of times. No noticeable noise after that. Worth a try and easy.

[balibeemer]

1. Remove brake pads.
2. Smear a thin film of lithium grease on the back face of the pad.
3. Replace pads

No squeak

[Bob_Roller]

When I got my '81 R65 from the dealer, the brakes squealed the first time I applied them, the bike had 5 miles on it .

[Luca]

Even with a clean setup, new springs, and EBC organic pads I still squeal under low speed light braking.  Perhaps the rotors need another cleaning.

I agree with Mike that brake squeal should be looked at from a "what is wrong" perspective and not just with a "that's the way it is" attitude.

But at the same time our disc brakes (like most) come with anti-rattle springs because vibration at the pads is inherent to disc brake design.  Not sure if I'd write off a product that, though by a different method, accomplishes the same thing as anti-rattle springs...

In fact, brake pads on new(er) autos use thin, slightly springy shim stock on the backs of the pads instead of pin-mounted anti-rattle springs.

I also wonder if the factory stainless rotors are more prone to squealing?

[Bob_Roller]

I replaced the original pads on my '81 R65 at 45,000 miles with OEM pads and the squeal came back on the first ride .

At 74,000 miles the rotors were worn out and I replaced them with EBC steel semi floating rotors and EBC graphite pads and no squeal in the last 6 years .

Maybe the stainless rotors are a factor in this .

[georgesgiralt]

I have rotors which are cast iron. (I do not know the make and they look like the OEM stainless ones as they have exactly the same pattern regarding the holes).
They squeal heavily under the rain be it with OEM or EBC pads. Pressure to apply under rain is monstrous. I fear emergency braking in such conditions.
When the bike was new, she had ATE callipers. Squealing all over. When I switched to Brembos because the Ate where toast, the squealing disappeared altogether...

[TXRider60]

I have rotors which are cast iron. (I do not know the make and they look like the OEM stainless ones as they have exactly the same pattern regarding the holes).
They squeal heavily under the rain be it with OEM or EBC pads. Pressure to apply under rain is monstrous. I fear emergency braking in such conditions.
When the bike was new, she had ATE callipers. Squealing all over. When I switched to Brembos because the Ate where toast, the squealing disappeared altogether...

Merci Bien, Georges!

[Barry]

The OEM stainless steel rotors are certainly very scary in the wet. Interesting that Georges cast iron rotors were also poor.

Is there any type of rotor that isn't hopeless in the wet ?

[Bob_Roller]

I've got EBC semi-floating steel rotors and EBC graphite pads on my '81 R65 .

That combination works well for me, I've had two times when I was in a thunderstorm with heavy rainfall water 'ponding' and running down  the roads and had very adequate braking for the conditions, I was actually surprised by the braking action .

I don't get to 'enjoy' very many wet weather riding occasions living in a desert .

Before I replaced the OEM rotors and pads, I would not ride the R65 if there was a chance of wet conditions .

Now, unless it's forecast to be an all day rain event, I have no qualms about riding the R65 in wet conditions .

Usually, I make my decision on leaving home, if it's raining when I leave, I take the Honda to work .