Got my money's worth out of these brake pads....
03-29-2005, 07:25 AM
#13
there's 3 ways I know of to check for rotor replacement...
1) It's warped or grooved, doesnt matter how much life is left, replace it. It warps from abuse it can't handle, it grooves from backing plates on the disc instead of pads. Really soft discs (like stock) will groove from soft pads (like stock) just from the tempurature abuse (see picture):
<img src="http://www.boom.net/~ryans4/StasisBrakes/a1.jpg">
2) Measure the disc thickness in like 10 different spots and average it out. Your disc started at 32mm thickness, with a 16 mm (probably) air gap, which gives you 8mm plate thickness when new (per side). I'd say once the plate thickness is down to 4mm (per side), it's probably time to replace. The easy way to tell this though is that there will likely no longer be slots once you've worn 4mm down on the disc plate. So if you can't see slots, probably time to replace.
3) For those that run track pads, don't warp discs, and run them hard, the discs will crack before they run out of plate thickness. If the setup is working well, the cracks will start small, at the center of the disc, and start to work there way to the edges. Once they hit the edge of the disc, replace.
<img src="http://www.boom.net/~ryans4/StasisBrakes/a1.jpg">
2) Measure the disc thickness in like 10 different spots and average it out. Your disc started at 32mm thickness, with a 16 mm (probably) air gap, which gives you 8mm plate thickness when new (per side). I'd say once the plate thickness is down to 4mm (per side), it's probably time to replace. The easy way to tell this though is that there will likely no longer be slots once you've worn 4mm down on the disc plate. So if you can't see slots, probably time to replace.
3) For those that run track pads, don't warp discs, and run them hard, the discs will crack before they run out of plate thickness. If the setup is working well, the cracks will start small, at the center of the disc, and start to work there way to the edges. Once they hit the edge of the disc, replace.
03-29-2005, 07:34 AM
#16
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Yeah, I guess so! Note to self: Take foot off brake going down straight! ;-) Question for ya...
Looking at your brake pads. I was sent some Kerr Friction's race pads when I bought my BBK from Stoptech(part of Achtuning special of free fluid and race pads way back). Well the rears were fine, but the front pads seemed to stick out past the edge of rotor. Even seated in the ST caliper right there was wear on the pad but to the outermost part there was a lip where it wasn't worn or touching the rotor. So it was like it would be rubbing on the outer/topside of the rotor. Could you see this as an issue? Do you understand what I mean? HAHA
03-29-2005, 07:43 AM
#17
the pad overhangs the disc edge is what you are saying yes?
if so, how much?
1mm is fine.
over 2mm is NOT ok. It will over time develop a ridge on the top of the pad, that will in street driving cause a harmonic noise (think of drawing your finger along the rim of a ((nice)) wine glass).
If it's a track pad only and that's the case, then after each event, when you pull out hte pads, take a file and grind off the ridge before you use them again.
Ideally (IMO) you want the pad right at the edge of the disc. The disc will grow in diameter under heavy abuse, so you want the pad at the edge of teh disc (even 1mm over is "ok") so that when the disc grows, you're still getting good pad contact.
Another reason is if the pad is set in a couple MM (like stock) you develop this huge lip on teh disc that makes getting the pads out a PITA.
So first, figure out how much they are overhanging. If it's like 5mm, they are not right and should be returned for replacment.
1mm is fine.
over 2mm is NOT ok. It will over time develop a ridge on the top of the pad, that will in street driving cause a harmonic noise (think of drawing your finger along the rim of a ((nice)) wine glass).
If it's a track pad only and that's the case, then after each event, when you pull out hte pads, take a file and grind off the ridge before you use them again.
Ideally (IMO) you want the pad right at the edge of the disc. The disc will grow in diameter under heavy abuse, so you want the pad at the edge of teh disc (even 1mm over is "ok") so that when the disc grows, you're still getting good pad contact.
Another reason is if the pad is set in a couple MM (like stock) you develop this huge lip on teh disc that makes getting the pads out a PITA.
So first, figure out how much they are overhanging. If it's like 5mm, they are not right and should be returned for replacment.
03-29-2005, 07:50 AM
#18
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Yes overhang, like 1-2mm. It's not bad. They are JUST track pads and I was thinking of...
doint what you said and just filing them down to existing wear level. I just didn't know while AT the track it would cause an issue. Thanks
03-29-2005, 07:54 AM
#19
no, you'll be fine at the event...
...if you get them hot enough, you may not need to file them down as the disc growth will knock off the ridge.
And when filing brake pads, wear a mask.
And when filing brake pads, wear a mask.
03-29-2005, 07:55 AM
#20
AudiWorld Expert
Thread Starter
thanks again Ryan - I'll check #2, though I might need to get one of those curved measuring calipers
as I have a small lip at the edge of my rotor, which would make measuring it with a standard caliper difficult.
I still have obvious slots though.
I still have obvious slots though.