Unusual Pad and Disc Wear
09 December 2016, 06:29 PM
#1
Unusual Pad and Disc Wear
I had to replace a wheel stud on the offside front today, so I took the opportunity to inspect the brakes. What I discovered was some unusual wear to both the pads and discs, which I was hoping someone could advise as to the cause.
The brakes are AP CP 5000, with 315mm discs and DS2500 pads.
Two raised ridges on disc:
Grooves in Pad:
Rear of disc with three ridges:
Rear pad:
Disc again:
The disc measured 18.5mm thick and you can see that the surface cooling grooves have almost worn away. Compare to the NSR:
You can see that the grooves are still visible and it measured 19.5mm thick.
Calipers were rebuilt with stainless steel pistons and the discs and pads were all fitted at the same time. It's been MoT'd recently and they did comment on the uneven wear but said that braking wasn't effected. The calipers don't have dust boots but there is no evidence of a piston sticking; the car still brakes strong and straight.
You can see from the Pad photo that although there is plenty of material left, a couple of rivets are wearing through already. Also material has disintegrated from the corners. I've probably done 30k plus on them but 85% M-Ways and it hasn't been on track.
I guess I'll need new pads and probably the discs skimmed but could there be anything else amiss, rather than simply the pads?
The brakes are AP CP 5000, with 315mm discs and DS2500 pads.
Two raised ridges on disc:
Grooves in Pad:
Rear of disc with three ridges:
Rear pad:
Disc again:
The disc measured 18.5mm thick and you can see that the surface cooling grooves have almost worn away. Compare to the NSR:
You can see that the grooves are still visible and it measured 19.5mm thick.
Calipers were rebuilt with stainless steel pistons and the discs and pads were all fitted at the same time. It's been MoT'd recently and they did comment on the uneven wear but said that braking wasn't effected. The calipers don't have dust boots but there is no evidence of a piston sticking; the car still brakes strong and straight.
You can see from the Pad photo that although there is plenty of material left, a couple of rivets are wearing through already. Also material has disintegrated from the corners. I've probably done 30k plus on them but 85% M-Ways and it hasn't been on track.
I guess I'll need new pads and probably the discs skimmed but could there be anything else amiss, rather than simply the pads?
09 December 2016, 09:49 PM
#2
Scooby Regular
A couple of observations...
The grooves in the outer faces of the discs are pad cleaning grooves.
If the disc is down to the point where the grooves have disappeared then its time to look at replacement.
The thinnest 315mm disc I can see suitable for a CP5000 caliper is 25.4 mm
https://www.apracing.com/products/ra...3%B8315mm.aspx
The grooves in the outer faces of the discs are pad cleaning grooves.
If the disc is down to the point where the grooves have disappeared then its time to look at replacement.
The thinnest 315mm disc I can see suitable for a CP5000 caliper is 25.4 mm
https://www.apracing.com/products/ra...3%B8315mm.aspx
10 December 2016, 12:41 PM
#5
I would have still thought that the discs would outlast the pads? What do you make of the uneven pad wear? I don't think that I'll be buying DS2500s again based upon this evidence.
I guess that it's an opportunity to go to 28*330mm discs. I'll need to get some spacers for the calipers and probably longer bolts too though.
I guess that it's an opportunity to go to 28*330mm discs. I'll need to get some spacers for the calipers and probably longer bolts too though.