Intermittant Brake Vibration With Light-Medium Pressure
 

I'm experiencing a strange issue. I changed my brake pads, performed the beading procedure and I now have a intermittent, fairly severe vibration under braking.

If I'm driving around the issue will occur when I apply the brakes with light to medium pressure. If I stomp harder on the brakes, the problem goes away for a while. 5 mins later the issue returns. The caliper and pads seems to slide back and forth with ease.

Any ideas?

The same thing happens on my son's 300zx. I haven't really looked into it.
Did you have the brake rotors turned? There could be a buildup of the old pad left on the rotor.

You may not have done the beading procedure correctly?

I didn't turn the rotors, but they seemed pretty smooth and they didn't have too much use on them. I'll try the beading procedure tonight again and update. I'm pretty confident that I did it correctly the first time...

What kinda brake pads?

Sounds like what I experience when I overheated the brake pads on the track.

Wonder if you were too aggressive in your bedding?

Hawk HP+. It was wet out when I did it. I thought I was within the range of the instructions, but I suppose it's possible...

Why not just buy new rotors?

The vibration is the pad getting "kicked" off the rotor either from warping or incorrect assembly. You can easily tell if a rotor is warped by looking for uneven contact "sheen". If your rotors look OK, then double check your assembly torques, your calipers may have simply come loose during break-in.

You may have slightly warped rotors. I always change mine with the break pads

I did the bedding process again. It didn't help. I'm always suspicious of the top caliper pins with their rubber lining. I tried swapping it out with a bottom pin (ie. two bottoms). Didn't help. Then I did a track day. The problem appears to solved. I'm not exactly certain why, but I think I'm okay with it. :)

I didn't replace the rotors because they're expensive in Canada. I think I will make a point of having them resurfaced next time.

Thanks for all of the responses.

Aren't the bottom pins supposed to have the rubber lining?

You are correct, I had mine in the wrong position. I don't really understand the purpose of the rubber linings...

Me neither. I hope someone can point that out :) and why do the rears not have them, unless it has something to do with the fronts compress and the rears twist.

Doesn't mention anything about the rubber lining, but here's a very informative post you should take time to read: BRAKE FAQ