sweetm3 180 Report post Posted October 27, 2010 (edited) Questions that have arisen What could be the cause of the uneven pad wear? Calipers not balanced, Left side brake cooling duct not connected, right side connected so may be pads not reaching the correct operating temperature? What could be the cause of the wear ring on the rotors near the bottom of the slots? my setup for the track BMW E36 M3 1997 3.2 Front RB 400 Calipers 4 pot, RB 2 piece rotors 328 X 28, RB Et 900 pads Rear Standard calipers (brass guides), RB 2piece rotors 312 X 20, Hawk DTC-60 pads Race brake fluid Bedding in of the brakes pads and rotors were completed as per instructions. On the day at Hampton Downs, 4 groups, 15 minute sessions so approx 45min between sessions. Ambient temps between 18-20 OK I was taking temperature readings on my rotors after the cool down lap, the front were reading 210F and the rears were 420F, drivers side only. But still knocked 3.7 seconds off my previous fastest lap time now down to 1.21.1 As you can see I was pushing it and the brakes worked a treat, no fade, pulling up nice and straight and balanced. Time to change back to my street pads, so what did I find, I have included some photos of my rotors and pads. measurements of brake pad wear (looking from the rear) Front, RB Et 900 pads new 17.6mm left side 14.5mm (1 pad separating hard to see in photo) right side 12.8mm (1 pad separating see photo) Rear , Hawk DTC-60 pads new 15.92mm left side 15.4mm/ right side 15.3mm Rotors Thickness Wear: measured not worth mentioning Surface/Face condition: Fronts not as smooth as glass anymore, both fronts do have a strange wear ring at the bottom of the slots (low spot) Rears: not as smooth as glass anymore but even wear characteristic. I havent done that many km's on my street pads but they seem to be wearing fairly evenly thanks for having a look Edited January 27, 2011 by sweetm3 Quote Share this post Link to post Share on other sites
E30-323ti 66 Report post Posted October 28, 2010 Have you got the rotors & calipers on the right sides?? The slots & venting (assuming radial vents as per the stock rotors) should 'fling' the air outwards. Looking at the 'front right' photo, the arrow on the caliper is pointing down ie direction of rotation. Given the bleed screws are on the top I can see why you put them on that side, but you often need to swap the fluid cross-over & bleed nipples over with 'generic' calipers. I gather the calipers have staggered pistons, thus the direction arrow. Either way, don't sort your problem, as the above would result in tapered pads, not un-even left to right wear. Which suggests it is a temperature issues as you mentioned you only had the one brake duct connect. Goodness knows why, all or nothing!! The wear ring you mention is probably due to the pads being narrow than the friction ring. Quote Share this post Link to post Share on other sites
sweetm3 180 Report post Posted October 28, 2010 Ah yes the arrows, now thats another story and CU by racingbrakes USA. But the calipers and rotors are mounted right way round. Quote Share this post Link to post Share on other sites
|ncary 0 Report post Posted October 29, 2010 'ang on a minute. The calipers are indeed backwards. If that actually is the front right (it should be because the caliper is on the side of the hub closest to the rear of the car) then the rotor will be turning clockwise, where as the arrow is pointing counterclockwise. There looks to be a alternative location for the bleed nipple on the caliper at the other end of the Racing Brakes logo. Have they sent them to you with the nipple in the wrong place? Who knows really.. As for uneven wear, if only 1 brake duct is connected, then that is for sure a major part of the reason. Also Hampton is mostly right hand turns, so the left side front brake will do a lot more work, but that is the pad which is worn out less... Ahaa tricky, tricky problem.. Quote Share this post Link to post Share on other sites
sweetm3 180 Report post Posted October 29, 2010 Sorry I always describe left and right on my car from the prospective of looking forward from the drivers seat. Quote Share this post Link to post Share on other sites
|ncary 0 Report post Posted October 30, 2010 Are you taking the piss???!? Man oh man, in your own help-wanted thread of all places! ugh It is undeniable that the calipers are on the wrong side of the car. The bleed nipple needs to be removed and put at the other end of the caliper. This probably has nothing to do with the uneven wear issue but if the larger piston pair of the 4 pistons was leading with my new BBK then I'd rectify that immediately. Didn't these people screw you around with some issue in your first thread about BKK's? Trusting that they have most likely pulled these symmetric mass-fit calipers out of a bulk box and sent them to you with the bleed nipple on the wrong end :) :) :) :) Quote Share this post Link to post Share on other sites
sweetm3 180 Report post Posted October 30, 2010 Thanks for the reply Incary, Read your post #4 at 5.30 am long night and got it wrong. As for post # 6 all help is appreciated Cheers Quote Share this post Link to post Share on other sites
sweetm3 180 Report post Posted January 27, 2011 Update Finally got back to Hampton Downs on Monday, new Hawk DTC 70 up front, I sealed off the driver’s side(Ha Ha) brake duct. New lap time of 1.20.65 Removed and measured the pads today, this time there was less than a millimetre of wear off each pad(both sides). Nicer wear pattern on the rotors as well. So the pads were not reaching operating temperatures on the driver’s side, so problem solved. Quote Share this post Link to post Share on other sites
hybrid 1039 Report post Posted January 28, 2011 Most front BMW calipers are bolted to the front of the disc. Which would of given it away in the photos rotation looks fine in the photos Quote Share this post Link to post Share on other sites
JFry 1 Report post Posted January 28, 2011 Most front BMW calipers are bolted to the front of the disc. Which would of given it away in the photos rotation looks fine in the photos My E36 has them closest to the rear, same as Incary has pointed out? Quote Share this post Link to post Share on other sites
hybrid 1039 Report post Posted January 28, 2011 you know when I re-read that .. I had a blonde moment. I see how easily it could of been mistaken. Quote Share this post Link to post Share on other sites
|ncary 0 Report post Posted January 29, 2011 Haha yeah you can see the trailing arm bushing mount thing in one of the photos there, indicating which way is actually forward. Did you ever swap the calipers around sweetm3? Quote Share this post Link to post Share on other sites
