Rear pad taper/ caliper piston warp??
12-09-2011, 07:03 PM
#1
Burning Brakes
Thread Starter
Rear pad taper/ caliper piston warp??
Hey guys,
Does anyone else get this. Stock rear c5z calipers using XP 8 pads. I get a bit of pad taper in the rear, not enough to need to rotate pads and it doesnt seem to shorten the usable life at all, but after a few track days there is definitly a bit of taper on them.
Also, the bottom of the piston where it does not make contact with the pad backing plate has deformed a bit and made a small lip that rolls under the pad about 1/16". It doesnt seem to mess with anything as every set of pads fits right into the lip the same, just curious if anyone else has seen this?
I drive with all of the nannies off so there is no issue with the AH dragging the rear brakes, pad wear is equal on both sides of the car, and I use about 2 sets of front pads for every 1 set of rears.
Normal?
Does anyone else get this. Stock rear c5z calipers using XP 8 pads. I get a bit of pad taper in the rear, not enough to need to rotate pads and it doesnt seem to shorten the usable life at all, but after a few track days there is definitly a bit of taper on them.
Also, the bottom of the piston where it does not make contact with the pad backing plate has deformed a bit and made a small lip that rolls under the pad about 1/16". It doesnt seem to mess with anything as every set of pads fits right into the lip the same, just curious if anyone else has seen this?
I drive with all of the nannies off so there is no issue with the AH dragging the rear brakes, pad wear is equal on both sides of the car, and I use about 2 sets of front pads for every 1 set of rears.
Normal?
12-09-2011, 07:17 PM
#3
Burning Brakes
Thread Starter
12-10-2011, 03:57 PM
#5
Race Director
Hey guys,
Does anyone else get this. Stock rear c5z calipers using XP 8 pads. I get a bit of pad taper in the rear, not enough to need to rotate pads and it doesnt seem to shorten the usable life at all, but after a few track days there is definitly a bit of taper on them.
Also, the bottom of the piston where it does not make contact with the pad backing plate has deformed a bit and made a small lip that rolls under the pad about 1/16". It doesnt seem to mess with anything as every set of pads fits right into the lip the same, just curious if anyone else has seen this?
I drive with all of the nannies off so there is no issue with the AH dragging the rear brakes, pad wear is equal on both sides of the car, and I use about 2 sets of front pads for every 1 set of rears.
Normal?
Does anyone else get this. Stock rear c5z calipers using XP 8 pads. I get a bit of pad taper in the rear, not enough to need to rotate pads and it doesnt seem to shorten the usable life at all, but after a few track days there is definitly a bit of taper on them.
Also, the bottom of the piston where it does not make contact with the pad backing plate has deformed a bit and made a small lip that rolls under the pad about 1/16". It doesnt seem to mess with anything as every set of pads fits right into the lip the same, just curious if anyone else has seen this?
I drive with all of the nannies off so there is no issue with the AH dragging the rear brakes, pad wear is equal on both sides of the car, and I use about 2 sets of front pads for every 1 set of rears.
Normal?
I would think that's a major problem, like the wrong pads are being used.
Is this truly what you are describing?
I will need to double check mine & will follow up.
12-10-2011, 06:42 PM
#7
Burning Brakes
Thread Starter
Thats exactly what I am describing. I would take pictures of it, but I am out of the country for work and will not be home for a couple weeks still.
On the rear calipers the bottom (closest to the hub center radius wise) 1/16" or so doesnt make contact with the pad. The rear calipers/brackets/slides are all stock and I use Carbotech XP8 pads. Every set I have had on there fits like that. Both sides have the exact same imprint on the piston. Its hard to notice if you are not looking for it, and I just happened to see it once when cleaning the calipers before putting a fresh set of rear pads on.
If this is not normal, what could cause it? I cant think of how the stock caliper could flex and allow this, and al of the stock parts dont allow any adjustment for it. The only thing I could think of would be the pads, but what are the chances of getting multiple wrong sets from Carbotech over a period of a couple years and nobody else having this issue?
I wish I had the parts in front of me to confirm, but IIRC the pad backing plate width is smaller than the OD of the rear caliper piston by a small bit.
The fronts do not have this issue FWIW.
On the rear calipers the bottom (closest to the hub center radius wise) 1/16" or so doesnt make contact with the pad. The rear calipers/brackets/slides are all stock and I use Carbotech XP8 pads. Every set I have had on there fits like that. Both sides have the exact same imprint on the piston. Its hard to notice if you are not looking for it, and I just happened to see it once when cleaning the calipers before putting a fresh set of rear pads on.
If this is not normal, what could cause it? I cant think of how the stock caliper could flex and allow this, and al of the stock parts dont allow any adjustment for it. The only thing I could think of would be the pads, but what are the chances of getting multiple wrong sets from Carbotech over a period of a couple years and nobody else having this issue?
I wish I had the parts in front of me to confirm, but IIRC the pad backing plate width is smaller than the OD of the rear caliper piston by a small bit.
The fronts do not have this issue FWIW.
12-10-2011, 07:16 PM
#8
Supporting Vendor
Member Since: Oct 2002
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St. Jude Donor '11,'13
Thats exactly what I am describing. I would take pictures of it, but I am out of the country for work and will not be home for a couple weeks still.
On the rear calipers the bottom (closest to the hub center radius wise) 1/16" or so doesnt make contact with the pad. The rear calipers/brackets/slides are all stock and I use Carbotech XP8 pads. Every set I have had on there fits like that. Both sides have the exact same imprint on the piston. Its hard to notice if you are not looking for it, and I just happened to see it once when cleaning the calipers before putting a fresh set of rear pads on.
If this is not normal, what could cause it? I cant think of how the stock caliper could flex and allow this, and al of the stock parts dont allow any adjustment for it. The only thing I could think of would be the pads, but what are the chances of getting multiple wrong sets from Carbotech over a period of a couple years and nobody else having this issue?
I wish I had the parts in front of me to confirm, but IIRC the pad backing plate width is smaller than the OD of the rear caliper piston by a small bit.
The fronts do not have this issue FWIW.
On the rear calipers the bottom (closest to the hub center radius wise) 1/16" or so doesnt make contact with the pad. The rear calipers/brackets/slides are all stock and I use Carbotech XP8 pads. Every set I have had on there fits like that. Both sides have the exact same imprint on the piston. Its hard to notice if you are not looking for it, and I just happened to see it once when cleaning the calipers before putting a fresh set of rear pads on.
If this is not normal, what could cause it? I cant think of how the stock caliper could flex and allow this, and al of the stock parts dont allow any adjustment for it. The only thing I could think of would be the pads, but what are the chances of getting multiple wrong sets from Carbotech over a period of a couple years and nobody else having this issue?
I wish I had the parts in front of me to confirm, but IIRC the pad backing plate width is smaller than the OD of the rear caliper piston by a small bit.
The fronts do not have this issue FWIW.
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Adam Adelstein
Amp’D Autosport.com
Internet's largest retailer of Carbotech Performance Brake Pads.
PH:216-780-8825.
Email: sales@ampdautosport.com
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Adam Adelstein
Amp’D Autosport.com
Internet's largest retailer of Carbotech Performance Brake Pads.
PH:216-780-8825.
Email: sales@ampdautosport.com
Web Site & Direct ordering http://ampdautosport.com/
All major CC and Pay Pal accepted.
Check out Promo code:z28
12-10-2011, 07:24 PM
#9
Race Director
These are some spares probably HP+ and I think some are stock c5z pads, so obviously the piston does not 100% contact the backing plate.
You are fine, good observation.
As others stated "some" pad taper is normal in track/autox use. I flip mine to even it out.
As for the deformation on the piston itself, I would be a little bit concerned on that, if only because if the piston were to rotate at all then you could have an uneven contact area (and you already know you don't have 100% contact to begin with, by design).
A nice upgrade would be to stainless steel cups/pots, they transfer less heat to the caliper & probably would not get a "dent" in the edge.
Last edited by froggy47; 12-10-2011 at 07:31 PM.
12-10-2011, 08:35 PM
#10
Burning Brakes
Thread Starter
When you can post pics or send them to me adam@ctbrakes.com
12-10-2011, 08:43 PM
#11
Burning Brakes
Thread Starter
These are some spares probably HP+ and I think some are stock c5z pads, so obviously the piston does not 100% contact the backing plate.
You are fine, good observation.
As others stated "some" pad taper is normal in track/autox use. I flip mine to even it out.
As for the deformation on the piston itself, I would be a little bit concerned on that, if only because if the piston were to rotate at all then you could have an uneven contact area (and you already know you don't have 100% contact to begin with, by design).
A nice upgrade would be to stainless steel cups/pots, they transfer less heat to the caliper & probably would not get a "dent" in the edge.
I have considered upgrading them, but they really havent caused any issue in performance so I have just been keeping an eye on it. They have not rotated on me at all, but if it becomes and issue I will definitely do something about it. I wonder why they are designed with less than 100% contact area?
Thanks for the effort and for the pictures in advance btw.
01-10-2012, 04:51 PM
#14
Burning Brakes
Thread Starter
Not to bring a thread back from the dead, but here are the pictures from my calipers for future reference. As you can see there is a very slight lip that has formed where the piston does not contact the caliper.
01-10-2012, 05:10 PM
#15
Burning Brakes
My rear calipers did the same thing as yours. I always wondered if that might be a problem but I've run it for two years now that way and never had an issue.
01-12-2012, 06:58 PM
#18
Race Director
they don't look that bad to me, as long as the part that goes into the bore is not deformed it should not effect function. I've melted the pistons out of front calipers before, but I wouldn't expect it in the rear. A set of SS/Ti/Si shields could help also.
01-15-2012, 02:46 AM
#20
that "lip" on the outside edge is weird but seems benign. as far as overall shape of calipers - i used to get mine looking a lot more beat up than that before replacing.
if you notice heavy inside-to-outside taper it's a sign that aluminum has lost its rigidity, the caliper is spreading, and things are not well. if you like to use your brakes and tires to the limit of their capability, it will happen sooner or later, on both axles.
if you notice heavy inside-to-outside taper it's a sign that aluminum has lost its rigidity, the caliper is spreading, and things are not well. if you like to use your brakes and tires to the limit of their capability, it will happen sooner or later, on both axles.
