New brake pads still squealing

So I got new front brake pads a few months ago for my 82' 550 and chamfered the edges down but they squealed during the last few yards to a complete stop, typically when going slow. I thought it was part of the brake-in, but after a few months I took them off again, re-chamfered them, really good this time, I even applied that red goop to the back of the pads that is supposed to eliminate vibration, and finally I wet sanded with 1000 grit the rotor and smoothed the whole thing. Get on to ride next day... still squealing... what's the deal? Are the pads I got just not good with the original rotor I have? Am I missing something??

 

Changing the chamfer shouldn't be required. The pads are designed to fit and work correctly. When you do this you are simply masking another problem that exists.

What else have you done to the brakes? Did you rebuild the master cylinder and calliper? These should be overhauled every 2 years according to Yamaha. If there is corrosion binding the piston in the calliper, it can cause a squeal. Put the bike on the centre stand and try to spin the front wheel. It should spin with no drag. Apply the brake and see if it stops and then fully releases after application.

If you haven't yet checked the date on the brake hoses, do so now. They have a 4 year life if they are "rubber." When doing a brake job it is usually wise to do a complete job, not just replace the pads.

Have you checked the rear shoes for de-lamination?

 

Adding a chamfer to new pads is a perfectly acceptable practice to alleviate squealing.

We'll start there: you cut a 45* chamfer about 1/4" wide on both leading and trailing edges?

See the diagram below; are you missing

-the pad shim?
-the pad anti-rattle spring? Is it correctly installed?
-either of the shim plates?




Did you rebuild the caliper?

Did you separate the caliper and the holding block, and clean/lube the sliding pin and shim plates so the caliper can slide back and forth in relation to the holding block?

Here's the deal: If you didn't rebuild the caliper, or tend to its ability to slide as above, it may be binding enough to drag when it gets hot, keeping the rotor and pads in constant contact and heating it up enough to make it squeal and squeak when you use it.

 

Like I said... Do a complete brake job, not just change the pads since the chamfer didn't stop the squeal. When you completely rebuild the brakes, you are going to have problems bleeding the system. Recommend that you obtain a vacuum bleeder. There are inexpensive units around that work quit well.

 

I think the "Pad Shim" is the most important thing to check for. Rick or Fitz will correct me if i'm wrong, but i'm pretty sure that that shim will make the pad engage the disc at an angle (a very small one at that) and then as you squeeze more it will press the complete pad against the disc.

If you don't have this shim, the whole flat face of the pad will engage the disc at light brake pressure levels and can cause the "squeak".

 

I don't have the shims, I thought that the anti-vibration goop I put on would solve that issue. Should I get new OEM style pads that come with shims and just put those on?

 

Where are you going to find those?

Unfortunately, the "goop" won't do it; you need the silly "half-shim" on the piston-side pad. I don't know that OEM pads come with the shims any more; even aftermarket replacements USED TO, but none I've seen recently do.

Here's a diagram including pic if you want to make one; I believe you will need to "mirror" it since I used a RH caliper and yours is on the left (but the same otherwise.)

 

Sometimes, ...

Eliminating Brake Squeal is as easy as removing the harsh Right Angles on the New Pad.

The process is called: Chamfer-ing

Just "Round-off" the Sharp Edges on the Pads.

 

You misplace your spectacles Rick i know your a year older and all but..

He's already tried to chamfer them

 

I'm too old.

I should sell both bikes and get one of those fancy-schmancy all-pimped-out Golf carts to run-around in.

Although my Birthday isn't 'till Sunday!