1982 XJ650 Squealing Front Brake

Since I finished the restoration on my 1982 Maxim 650, the front brake caliper has squealed like Banshee in a fire pit. The brake pads are new (Vesrah brand) and I have tried greasing the contact points, replacing the top vibration clip, loosening the pivot bolt, and grinding a chamfer on the leading edge of the pads. It has improved slightly but it still squeals pretty loud. The wear on the pads is pretty uneven, so is it possible that the pads just need more time to wear down or should I try a different brand of brake pad? Also an important note is that the contact points on the pad are pretty worn down, as in metal in the backing plate has been ground away slightly and there is metal dust in the grease.

 

Did you remove the caliper and rebuilt it?
Most likely the piston seals have hardened, and are not letting the piston relax back into the bore enough.
You should also make sure that the bushing for the pivot bolt, and the bolt itself, are clean and free of debris (but not greased).


The pads should not be worn to the point of the metal backer getting cut into, so those pads are now done for. The squeal you have is from the backing plate contacting the brake rotor.
New pads won't need anything done to them (no ginding or chamfering beyond what they come with from the manufacturer).

 

Its actually the back of the backing plate that is getting ground, the sides that contact the piston and caliber bracket. There is little to no friction material removed from when they were new. I have not rebuilt the caliper though, but I should point out that the squealing only happens when braking at lower speeds (<30 mph). The wheel spins freely with no brake applied. Also, why no grease on the pivot bolt and bushing?

 

That o-ring does not provide a great seal in my opinion. Grease on the pivot bolt and bush will attract dirt, and that will cause the parts to wear faster and even bind up. Graphite is preferred. If you do grease it, use a high-moly content grease and a new o-ring between the top washer and the caliper.

The nut that holds the bolt should not be run loose. Torque it to 18.8 ft lb.

The pad retaining pin needs to be shiny, smooth, and free of pits. Is it?
Is the spring for the pad retaining pin present?
The holes on the pads for the pad retaining pin might not be quite large enough, causing the pads to hang up. Using a file to open them up a bit is fine to do.

The calipers should be rebuilt every 4-10 years as a matter of course. Your life depends on the bike being able to stop reliably.
What are the date codes on the brake lines? Has the master cylinder been rebuilt?

 

What TYPE if pads are you running? Sintered metal pads take a while to break in and tend to be noisy.
If so give em time or switch to a Kevlar/carbon pad, they wear faster but are much quieter and not as hard on the disc

 

They are "organic" so i'm guessing that means they are carbon. The master cylinder was rebuilt in September but the lines are probably still the stock ones. I think I'm going to give it a month or two and see if it gets better, if it doesn't I'll switch to different pad. At some point I'll probably do a caliper rebuild as well.