Strange sound after changing rear discs and pads

[chapperzuk]

The rear brakes on my 197 were screeching when driving along due to them being lipped, so I had both the rear discs and pads changed with MTEC drilled and grooved discs, with Brembo pads.

However, I now hear a buzzing type sound when going along, which is pretty loud with the window down. Almost sounds like what a cable tie being dragged along the floor would sound like. Then when coming to a stop I'm hearing a high pitched sound until completely stopped.

Any ideas what would be causing this? Is there another part that's broken? Have they not been fitted properly? I've done over 1,300 miles on the new discs and pads.

Any advice would be much appreciated... Thanks!

 

[Ilikeminefast]

I have this aswell just assumed it was because of the grooves on the discs, will keep an eye on this post.

 

[Mentalpen]

you get rumble with grooved discs if the groves fill with pad after prolonged periods of heavy breaking.

 

[lemonnobby]

Are the disc sided.

 

[Alex.J]

You can run grooved discs both ways if they are grooved!

Each way has a slightly different effect!

One me is a cutting action and the other hot gas removal/pad friction material removal!

Which ever very way they run you will get noise from them!

They are probably binding slightly causing the initial noise, amplified due to the grooves!

 

[Leethelips]

you get rumble with grooved discs if the groves fill with pad after prolonged periods of heavy breaking.

i had drilled ( no grooves ) on the back of my E30 325i and under heavy breaking you could hear a popping noise as the air trapped in the holes expanded

 

[chapperzuk]

It just doesn't sound right to me. Not sure whether to take it to a garage or not? Either that or I just give them another thousand miles or so...

 

[Alex.J]

It just doesn't sound right to me. Not sure whether to take it to a garage or not? Either that or I just give them another thousand miles or so...

Just double check they are not binding mate! First port of call!

Do you have it so the grooves leading edge at the top is facing to the front of the car or rear?!

 

[Mentalpen]

if they are like the meg one side face forwards and one side backwards

 

[Rogue]

Did you get the caliper piston all the way back in when you changed the pads over as well?

I mean...all the way back.

 

[chapperzuk]

This is the drivers side rear...


This is the passenger side rear...


I don't think the callipers we're wound ALL the way back. Just enough to fit them over the discs.

 

[chapperzuk]

Here's a quick video with the car jacked up and me spinning the wheel...

http://youtu.be/RMAASE3XPKU

Any advice? I think the pad might be rubbing along the disc and the grooves in the discs are creating that noise as it rubs.

 

[Rogue]

I don't think you've pushed the calliper piston in enough. That would be my first port of call for elimination.

Take the wheel off, take the pad out, spin the disc. If you don't hear the sound you know what it is.

Obviously put a block under the wheels if you're taking off the hand brake...

 

[chapperzuk]

I don't think you've pushed the calliper piston in enough. That would be my first port of call for elimination.

Take the wheel off, take the pad out, spin the disc. If you don't hear the sound you know what it is.

Obviously put a block under the wheels if you're taking off the hand brake...

Thanks for the advice, much appreciated. I don't have the tool to wind back the calliper piston myself. I will either see if my mates do or take it to a garage.

Should it be wound all the way back, as far as it can go?

 

[Rogue]

Yeah, especially with new discs and pads.

It will be harder than you think because you're pushing fluid back into the system but once it gets going, it will go.

You can buy them in halfords, don't think they're that expensive.

 

[Foxspeed]

you will still get the pads touching the disc face - from the video it doesn't seem to be binding and spins easy - more than likely the new discs have still got a sharp leading edge on the hole/grooves causing the actual noise - even when worn off they will still produce some noise...

 

[chapperzuk]

you will still get the pads touching the disc face - from the video it doesn't seem to be binding and spins easy - more than likely the new discs have still got a sharp leading edge on the hole/grooves causing the actual noise - even when worn off they will still produce some noise...

Would you say that it's normal then? Should I bother paying a mechanic to wind back the calliper pistons or just let everything wear in even more?

I've already done over 1,000 miles on these discs / pads though and that sound occurs when driving along. It's quite noticeable with the windows down.

 

[Mentalpen]

A rewind tool is like £5 for a crap one and £15 for a half decent one, just buy one and do it your self.

 

[Foxspeed]

if the brakes aren't binding I don't see the point of winding the pistons back in..they will only adjust back out

 

[Leethelips]

if the brakes aren't binding I don't see the point of winding the pistons back in..they will only adjust back out

Would agree with this seems a pointless exercise to me. Once you have braked they will be back to wear they are now.