weird grinding feeling from brakes

[Martin_172]

hi guys, getting a weird grinding feeling (thats all i can think of to explain it!) when breaking hard say from 100+ mph down to 60 or less

when i first start braking it feels fine and normal but then after say 5 or 6 seconds i get a grinding noise and feeling through the car/pedal its a similar feeling to when your cars been sitting for a while and the disks are rusted and you first brake, but the brakes still feel good and strong.

its fairly new pads and disks that are on it, i thought its possibly a warped disk but ive had one on my previous 1.2 and it was more a vibration, this is different.

is it something to do with the rear brakes getting more preassure on them (the disks are usually a bit rusty)?

cheers

 

[Josh@Renparts]

have you bedded the pads in ok? usually makes a noise when you are slowing down to a stop. Kind of a grumbling grinding noise.

 

[Henry]

the new discs aren't drilled/grooved are they?

 

[Christophe]

mine does it first thing in the morning sometimes but goes away after a minute. Usually happens once it been raining a lot. think its rust building up lol

 

[Martin_172]

standard disks, not drilled/grooved.

pads and disks have covered 10k/6months so not bedding in due to them not being brand new, just new-ish!

both disks look and feel ok but ive not had the wheels off yet for a proper look.

does the pressure on the rear brakes gradually increase when your braking hard without actually pressing the pedal any harder?

 

[RicardoAB]

I've got this on my new 197. The dealer said it was due to the material that they (not sure whether he means pads or discs) are made from.

A bit concerning tho for a new car and ones with Brembo's on. Is this normal on the 197?

 

[bmh.01]

Doubt it, there probably just lieing to you as per. So they don't have to do warrenty work.

 

[ditz]

it will be the abs you can feel! from those sort of speeds the tyres will be struggeling for grip on the back end due to weight transfer to the front.
go out on a quiet road and intentionally try to lock the wheels up, you will feel the same thing, the abs

 

[ditz]

mine does it first thing in the morning sometimes but goes away after a minute. Usually happens once it been raining a lot. think its rust building up lol

and that will be because the road is more slippery in the rain hence abs cutting in sooner

 

[.GAZ.]

I HAD 2 PUT NEW PADS ON THE CUP AFTER 6K

 

[edde]

Check the abs rings for rust etc I'd bet one is damaged.

 

[The Seer]

Mine are following the same symptoms as your's. There's a grinding sound, but much more noticeable at low speeds, though it is still there at higher speeds.

Suspect, as I've been told, that my discs are corroding. Now on 27K, still using 1st set of pads and discs.

Apparently the corrosion has taken place on the inside of the front discs.

 

[mattjk]

mines on first set at 29k, although they are getting thin now so will replace shortly

 

[Michael_L]

I have a grinding sound the first time I use the car on a morning, as others have suggested it could be atomspherics.

Did my front pads yesterday (on 29k, should have really done the discs too!) and mine still has it 1st thing on a morning. I might try new discs and pads all round next month after pay day!