robsta 0 Report post Posted April 30, 2008 Hey all, When braking- whether it be gently or hard -my front brakes are grinding sporadically. Since the noise has started there doesn't seem to have been any change in braking performance The pads are less than half worn and the disks have just been machined, so i'm assuming it is netiher of those. But what else could it be? Cheers Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted April 30, 2008 Hey all, When braking- whether it be gently or hard -my front brakes are grinding sporadically. Since the noise has started there doesn't seem to have been any change in braking performance The pads are less than half worn and the disks have just been machined, so i'm assuming it is netiher of those. But what else could it be? Cheers Possibly the cheap disc pads. Genuine wont do this. We deal with this just about every day. What brand are the pads....your answer may be there. Some disc machinists also dont know how to do there job properly as well...or use good quality cutting tools to do the job properly ( we have struck this ) Our present grinder does a great job. Quote Share this post Link to post Share on other sites
Butterfly 0 Report post Posted April 30, 2008 hi i have never heard of machining rotors wrong making a grinding noise u should check any metal clips or squeal shims to see if there touching the rotor. have u checked ur rear pads??? Quote Share this post Link to post Share on other sites
sp8s 1 Report post Posted April 30, 2008 Backing shims/retainers or the most common - a stone caught in the pad This catches a lot of people Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted April 30, 2008 (edited) hi i have never heard of machining rotors wrong making a grinding noise u should check any metal clips or squeal shims to see if there touching the rotor. have u checked ur rear pads??? BMW's don't have metal wear indicators (squeal shims) like the Jap cars have, and yes you can machine rotors wrong or badly if you dont do it properly or use the right tool tips in the disc lathe. Edited April 30, 2008 by botanymotorworx Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted April 30, 2008 Backing shims/retainers or the most common - a stone caught in the pad This catches a lot of people That is possible and it could also be a larger piece of metal in the metalic pad material causing the noise. I have seen this with some of the cheaper brands of disc pads. And BMW's dont have disc pad backing shims Quote Share this post Link to post Share on other sites
eurobandit 0 Report post Posted May 1, 2008 Hey all, When braking- whether it be gently or hard -my front brakes are grinding sporadically. Since the noise has started there doesn't seem to have been any change in braking performance The pads are less than half worn and the disks have just been machined, so i'm assuming it is netiher of those. But what else could it be? Cheers i would try sanding the leading edge of the pads this should fix for a while my personal opinion is replace brake pads when machining disks saves the time and hassle if this does happen,and i always use bmw parts not cheap parts. listen to botany he knows what hes talking about Quote Share this post Link to post Share on other sites
gmccormack 0 Report post Posted May 1, 2008 hi i have never heard of machining rotors wrong making a grinding noise u should check any metal clips or squeal shims to see if there touching the rotor. have u checked ur rear pads??? Bad machining can cause problems. I had it done once, it was a disaster. Caused a bad vibration through the pedal and a grinding noise. Quote Share this post Link to post Share on other sites
robsta 0 Report post Posted May 1, 2008 Cheers for the replies guys, I'm not sure what brand the pads are, will check tomorrow when I get a chance. The company who did the machining is pretty reputable in wellington so I don't think the job would have been below standard. I might just change the pads and see if that fixes it and take it from there! Quote Share this post Link to post Share on other sites
hybrid 1043 Report post Posted May 2, 2008 The other problem is cracking in the disc or as glen says .. sh*t pads. I had this problem on my old toyota celica. Cheap pads will defanitly cause the rubbing on concrete style sound. Quote Share this post Link to post Share on other sites