Rubbing Noise Under Hard Braking

[Evil Ally]

I've had DS2500's and Brembo HC discs on for about 15k. At the last trackday I was at, the front brakes (I'm not sure what side) started to make a rubbing/thrumming noise when they were up to temperature. This is only under hard braking, and doesn't happen when cold or not braking. I don't normally notice it on normal road driving either, I would say it takes a couple of runs up to 100 then down again to become apparent. I took the wheels off and there's plenty left on the pads and discs and nothing obviously wrong. The brakes seem to stop the car fine and there isn't any obvious vibration, but I'd like to get this sorted before it's out on track again. Any suggestions as to what I should look at?

 

[edde]

did you coper slip the pad up ?

 

[Evil Ally]

I didn't fit them, but they were copper slipped at the time. Do you think that's all it could be? I'm going to take the pads off today and take a closer look.

 

[edde]

I didn't fit them, but they were copper slipped at the time. Do you think that's all it could be? I'm going to take the pads off today and take a closer look.

have a look plug look for other loose things.

 

[MarkCup]

I've had this and cured it each time with a new set of calipers (on my 3rd set now).

I understand it to be the bushes that the caliper is mounted on wearing out a little, then when everything's up to temperature and you're really leaning on them...the caliper can move a little on them...sounds like a rubbing/grumbling sound.

http://www.youtube.com/watch?v=WD5zq0Jkpoo

On that video at 1:25 I brake from high speed and go down through the gears twice - and you can hear what I'm on about.

Is that what you're hearing?

 

[Gray]

I've had this and cured it each time with a new set of calipers (on my 3rd set now).

I understand it to be the bushes that the caliper is mounted on wearing out a little, then when everything's up to temperature and you're really leaning on them...the caliper can move a little on them...sounds like a rubbing/grumbling sound.

http://www.youtube.com/watch?v=WD5zq0Jkpoo

On that video at 1:25 I brake from high speed and go down through the gears twice - and you can hear what I'm on about.

Is that what you're hearing?

Just what I get under hard breaking :dapprove: booo!

 

[Evil Ally]

I've had this and cured it each time with a new set of calipers (on my 3rd set now).

I understand it to be the bushes that the caliper is mounted on wearing out a little, then when everything's up to temperature and you're really leaning on them...the caliper can move a little on them...sounds like a rubbing/grumbling sound.

http://www.youtube.com/watch?v=WD5zq0Jkpoo

On that video at 1:25 I brake from high speed and go down through the gears twice - and you can hear what I'm on about.

Is that what you're hearing?

That does sound kind of similar, oh dear :S Is this dangerous in any way? One thing I did notice, on the passenger side, the outside pad was a lot more worn than the inside. This was not the case on the drivers side. Do you think this could point to a defective caliper?

I took the pads out and gave everything a good clean and applied new copper grease. The roads were a bit too busy to give the brakes a workout, I'll try and test them later, fingers crossed.

 

[MarkCup]

I don't think it's dangerous...there's no risk the calipers are suddenly going to come away from the mounts...they just move a little, and let you know that with the grumbling noise.

I've been on track several times when they've been like that, they always perform exactly as they should...they just make that noise while they do it.