Brake girding noise/vibration with new discs and pads.

[Chrismartin]

Alright peeps

Two or three weeks ago I purchased and had fitted new brake discs (mtec drilled and grooved) all round and new pads (Project Mu HC800 front and NS400 back). Since then when I've been braking at slow creeping speeds or under reasonably hard braking from slow speeds I get a vibration through the pedal and a slight grinding noise. Appreciate this may be a noob ie question to some but could this be due to having grooved discs or could it he something wrong? Any advice would be greatly appreciated.

Kind regards
Chris

 

[spooke]

I too fitted some PMU NS400 pads onto OEM discs and after trying to bed them in the feont disc has glazed - which I believe is chasing a similar issue of a grinding/vibration on harder braking.

Check they aren't glazed over.

The below is from Project Mu (apparently),

1. Make sure the pads are installed correctly and check the pedal is firm before driving the car.
2. Drive somewhere with no traffic.
3. Do around 15-20 light brake applications from 80kph(50MPH) to 10kph(5MPH). Do not come to a complete stop.
4. Drive for approx 5 minutes with minimal brake use to allow them to cool slightly.
5. Do another 15-20 brake applications, this time from 100kph(60MPH) to 10kph(5MPH). Do not come to a complete stop.
6. Drive for at least 15 minutes with minimal brake use to allow the brakes to cool.
7. Park the car and allow the brakes to cool to ambient.
8. The pads should now be ready for use.
Notes:Always carry out a visual inspection of the brakes after they have cooled. Make sure the rotor face is in contact with the pads and no signs of glazing are present. If unsure of bedding result, re-do them.

 

[Chrismartin]

I too fitted some PMU NS400 pads onto OEM discs and after trying to bed them in the feont disc has glazed - which I believe is chasing a similar issue of a grinding/vibration on harder braking.

Check they aren't glazed over.

The below is from Project Mu (apparently),

1. Make sure the pads are installed correctly and check the pedal is firm before driving the car.
2. Drive somewhere with no traffic.
3. Do around 15-20 light brake applications from 80kph(50MPH) to 10kph(5MPH). Do not come to a complete stop.
4. Drive for approx 5 minutes with minimal brake use to allow them to cool slightly.
5. Do another 15-20 brake applications, this time from 100kph(60MPH) to 10kph(5MPH). Do not come to a complete stop.
6. Drive for at least 15 minutes with minimal brake use to allow the brakes to cool.
7. Park the car and allow the brakes to cool to ambient.
8. The pads should now be ready for use.
Notes:Always carry out a visual inspection of the brakes after they have cooled. Make sure the rotor face is in contact with the pads and no signs of glazing are present. If unsure of bedding result, re-do them.

Jesus that's a bit of a procedure. I've just been taking it easy since they were fitted 800 miles or so ago. Cheers for the information. Anything you can do when they're glazed?

 

[Chewy]

I could be wrong mind, but i don't think trying to bed the pads in over a glazed disk would do much good?

I believe you can remove the disks and sand off the glaze, then reassemble and try the above break in procedure again.

Have a word with your trusty mech mate he should be able to steer you in the right direction.

 

[Chrismartin]

I could be wrong mind, but i don't think trying to bed the pads in over a glazed disk would do much good?

I believe you can remove the disks and sand off the glaze, then reassemble and try the above break in procedure again.

Have a word with your trusty mech mate he should be able to steer you in the right direction.

Cheers mate but he isn't trusty at the moment haha.

 

[2ndy]

I would just stop taking them easy on them and it would probably sort them out

 

[Spoon_Sports_Europe]

Any discolouration to the rotor. Post pics

 

[integraleo]

Sounds like pad pick up to me,had similar issue with carbon Lorraine rc5+ pads. Track orientated pads don't tend to like gentle braking. I had new mtec grooved discs fitted and had pads refaced and it still done it. I ended up taking them off

 

[Chrismartin]

Cheers for the replies guys. It's much appreciated. I'm unsure because the Tegs the first car I've modified beyond cosmetically. Burn I shall take some snaps this morning and pop them online when im back from work. Cheers

 

[Spoon_Sports_Europe]

The HC800 and NS400 are meant to be street pads so this shouldn't be an issue. I'll keep an eye out for the pics.

 

[integraleo]

The HC800 and NS400 are meant to be street pads so this shouldn't be an issue. I'll keep an eye out for the pics.

The carbon Lorraine rc5+ pads are sold as a fast road/track pad. They have rc6 and even rc8 as pure track pads.

 

[Spoon_Sports_Europe]

The carbon Lorraine rc5+ pads are sold as a fast road/track pad. They have rc6 and even rc8 as pure track pads.

That's interesting, I wasn't sure about those so didn't comment.

 

[Chrismartin]

RIght guys. Here is the picture. Apologies for the quality of the image and how dirty the wheels are. Camera phone struggled to get the lighting right. Should be good enough anyhow.

 

[spooke]

It's hard to tell, but it looks like it may well be glazed, even if minor.

Best thing to do is to sand them down with a block, there are a few guides online on how do it, I'm also going to need to do it as mine are even worse looking.

 

[Chrismartin]

It's hard to tell, but it looks like it may well be glazed, even if minor.

Best thing to do is to sand them down with a block, there are a few guides online on how do it, I'm also going to need to do it as mine are even worse looking.

It didn't the vibration today. It seems quote intermittent which is annoying. Another annoying think is that they're squeeking a fair bit at creeping speeds. You noticed the same with the Mu pads?

 

[Spoon_Sports_Europe]

RIght guys. Here is the picture. Apologies for the quality of the image and how dirty the wheels are. Camera phone struggled to get the lighting right. Should be good enough anyhow.

There is something going on indicated by the darker line towards the middle of the disc. This is usually a sign of poor pad contact. Give them a bit longer to bed in or maybe follow the procedure as recommended by Mu above. The issue will then either go away of present its self more prominently.

 

[spooke]

It didn't the vibration today. It seems quote intermittent which is annoying. Another annoying think is that they're squeeking a fair bit at creeping speeds. You noticed the same with the Mu pads?

I was getting a squeak before bedding them in some more, I did try to sand the glaze off but realised the discs really need changing so instead have bought some new ones.

As above, give it some more time to bed in and it should hopefully settle.

 

[Chrismartin]

There is something going on indicated by the darker line towards the middle of the disc. This is usually a sign of poor pad contact. Give them a bit longer to bed in or maybe follow the procedure as recommended by Mu above. The issue will then either go away of present its self more prominently.

Thanks alos guys. Do appreciate the feed back alot. I'll try to keep this up to date for anyone else who may have similar problems in the future.

 

[hamks18psi]

I have installed the HC+800 front and NS400 rear, and have followed the bedding procedure pretty much.
First day is fine, everything seems ok, no squeal or vibration , and believe the bedding is done. Second day I have tired to drive as normal in town. No issue.
In the evening, I drove it for 30 minutes as fun to practise heel toe and double clutch. In the end of practice, on the way back home, I heard the squeal noise from the front.

I have started to test slow driving and brake it hard, then I have hear the squeal noise sometimes. It does not bother me much, and I expect it would squeal in low speed braking, these HC+ 800 I can feel it can kill the OEM disc quickly!
The most annoying thing is that in the moment during the stop, I heard the front brake pad noise thru the pedal, which felt like the rusty brake disc that has not been driven for long time, then in first few brake, that kind of feel. The noise is very different from what I experienced in the past. I did stop and check all four sides, the rear works perfect, no noise, disc looks good. The issue/sound are definitely from the front. I cool it down and did the test again, it is the same. It is difficult to describe the noise but there is NO vibration, the brake efficiency and performance works superbly well.

After reading this thread again and again, then I checked the old photos I took before the work started, and believe my front disc are glazed (not much, but some). But I also check other cars and neighbors' cars as well. I found lot of front brake disc have some glazed like effect. Also, I knew that my front OEM disc are not very good, and plan to get them replaced after the 1st track day event later. The noise now is a mystery to me, and I would take the wheel off and sand the front disc later, to see any help.

I don't think I have understood enough about glazed effect. After research online, I don't think my front disc have any glassy melt on it. Please advise.

 

[spooke]

I'd try and re-bed them, mine did this when I fitted PMU NS400 + OEM Brembo Discs. Could feel the vibration come through the whole car and they looked similar to yours. I tried sanding them down but that didn't really work, after trying to re-bed them it fixed it.

Edit - Just realised I've said the same thing as my last post