Brakes!!!

[focusxr5]

Little help required.

Recently had new pads and discs fitted to my Focus ST (2010). Just recently I noticed a slight knock come from the back. Through playing about a bit I noticed something. When I reverse and then brake, I hear a knock from the back of the car when I first hit the pedal. If I reverse further and brake again - no knock. If I then drive forward and brake, I'll hear a knock when I first touch the pedal. Continue driving normally - no more knocks. Unless I reverse again and then........well, you get the picture.

Any ideas?

[mackie1]

Could the pads have a slight amount of play in the carriers?

[BritishRacinGrin]

Were the new brakes fitted to the front or the back?

[focusxr5]

Sorry, should have clarified. It was new discs and pads all round. EBC Grooved and dimpled discs with Redstuff pads at the front and Blackstuff pads at the back.

[PhillipM]

Probably a slightly smaller backing plate than OEM and they're shifting in the carriers slightly.
Or the spring clips/riders were forgotten when the pads were swapped...

[itcaptainslow]

Sounds like the pads moving in the carriers. I wouldn't worry too much about it-several Citroen DS4's (as an example) I had all did this from the factory.

[BritishRacinGrin]

focusxr5 said:

EBC Grooved and dimpled discs with Redstuff pads at the front and Blackstuff pads at the back.

Eurgh. Why? Just... Why?

[focusxr5]

Thanks

My main concern was if it was something serious and I was going to hurtle off to put a hole in a hedge at any moment.

Cheers

[itcaptainslow]

focusxr5 said:

Thanks

My main concern was if it was something serious and I was going to hurtle off to put a hole in a hedge at any moment.

Cheers

Obviously we can only offer our thoughts based on your description and previous experience-I suggest for peace of mind if you're in any doubt to get the brakes inspected by someone qualified and experienced to do so.

[ikarl]

It's not uncommon for pads to sometimes move within the caliper, it may only be a small fraction but will make the noise you're talking about.

[Turkey]

Sounds like the pads might have been filed down to make them fit in the caliper. On old calipers there is sometimes rust behind the thin spring steel piece the pads slide on, which makes pads a tighter fit, so filing down the pads is necessary to make them fit. If you file down too much, you get a clunking noise as you describe the first time you change the direction of braking.

I don't think there's any safety issue with this.