Varelco 211 Report post Posted April 30, 2021 Hi All, I've recently had the 330mm AP Racing BBK fitted by Abbey Motorsports, I've noticed in reverse I get a loud clunk whenever I apply the brakes, is this normal? I've checked the anti rattle clip and its installed correctly but it does definitely sound like the backing plates of the pads moving. Share this post Link to post Share on other sites
will300 812 Report post Posted April 30, 2021 What type of disc's you running? I've had some noise when reversing with my grooved discs Share this post Link to post Share on other sites
Daninplymouth 61 Report post Posted April 30, 2021 Iv just had mine fitted and I get the same on the first time I brake when backing up. I have straight grooves if that makes a difference Share this post Link to post Share on other sites
Varelco 211 Report post Posted April 30, 2021 Straight groove discs fellas. Glad its not just me. Share this post Link to post Share on other sites
Mike 458 Report post Posted May 1, 2021 Everytime you brake in reverse or just the first time? Share this post Link to post Share on other sites
Varelco 211 Report post Posted May 2, 2021 Just the first time, all subsequent times its quiet. Share this post Link to post Share on other sites
Mike 458 Report post Posted May 4, 2021 Did you go for the floating disc option? They can clunk when you brake the first time in either direction, like the discs are shifting slightly. I get a clunk pretty much every time i brake when reversing. Doesn't seem to be an issue though... Share this post Link to post Share on other sites
Varelco 211 Report post Posted May 4, 2021 No I've got a traditional 2 piece setup. Looks as if its just a trait by the sounds of it! Share this post Link to post Share on other sites
Luke 193 Report post Posted June 9, 2021 I get that it could be a trait but it’s worth figuring out what is moving around to cause the clunk. How are you finding the feel of the AP compared to the oem brakes? Share this post Link to post Share on other sites
Daninplymouth 61 Report post Posted June 9, 2021 I suppose it could be the trait of 2piece discs and when you reverse there’s a bit of movement the other way. mine were fitted by TD and have the same Share this post Link to post Share on other sites
Varelco 211 Report post Posted June 9, 2021 1 hour ago, Luke said: I get that it could be a trait but it’s worth figuring out what is moving around to cause the clunk. How are you finding the feel of the AP compared to the oem brakes? Yeah I was intending to take a look actually, just to double check everything is still tight and as it should be. Pedal feel is much like stock day to day, no issues with modulation, the type of pad is going to make the most noticeable difference if anything, if I really stamp on the brakes I notice how much more stopping power have compared to the stock setup, the nose really dives. I've been really pleased with the Ferodo DS2500s, I was a little sceptical running that pad, they have good road manners, no noise issues, the feel and cold bite is pretty much how the stock setup felt, yet they have alot more capability when it comes to stressing them on track. Share this post Link to post Share on other sites
Mike 458 Report post Posted June 9, 2021 My theory on the noise is either the 2 piece discs shifting slightly - for those where it happens either direction and only once. Or the pads lifting up slightly and clunking in the caliper when braking in reverse which is what I have. Share this post Link to post Share on other sites
Varelco 211 Report post Posted June 9, 2021 I'm almost certain its the pads, the clunk sounds like the backing plates moving, nothing is translated through to the car, its just a light noise, they are the only moving part. I can't see how the discs would move, mine aren't floating just regular 2 piece, so they are bolted together, if they are moving then something is very wrong. If I was to hazard a guess I'd say the backing plates are slightly undersized in the caliper to allow expansion when they get hot, this would prevent them getting seized in the caliper. Share this post Link to post Share on other sites
Mike 458 Report post Posted June 9, 2021 I think the disc noise is for the floating option, where there's a tiny bit of play and you only get a noise when you brake the first time in whichever direction as the discs shift slightly. The pads / backing plates is what I'm certain I get as it makes sense its only in reverse as the pads bite, get lifted by the disc. No noise going forward as the pads bite and they've got nowhere to go downwards as they're already resting on the caliper Share this post Link to post Share on other sites
Leeky 84 Report post Posted June 9, 2021 Just curious, but is this a clunk on the front or the rear? I’ve recently fitted the Cosworth/APRacing 6pot/355mm front kit and the APRacing 4pot/335mm rear kit but cant say they’ve sounded any “clunkier” than stock. I wonder if clunking is something to expect/listen out for once the new pads have bedded in more. Share this post Link to post Share on other sites