Normal Wear for Brake Pads
12-10-2012, 10:05 PM
#1
Racer
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Normal Wear for Brake Pads
I am looking at possibly buying a CPO 2011 Carrera S with 12,000 miles, and I was told that as part of the CPO process, the rear brake pads had to be replaced, while the front pads were at 90%. Is this a normal wear pattern? Replacing pads after 12,000 miles in a normal car would seem very early, but I don't have any experience with a Porsche.
12-10-2012, 10:20 PM
#2
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Could be, since most of the traction/stability programs use the rear brakes to "anchor" the car. Not to say you wouldn't get more mileage out of the next set of pads. Also, since its being CPO'd they might have to meet a certain standard to be able to gain CPO certification.
12-10-2012, 10:31 PM
#4
Poseur
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As a long time 911 owner, I would first begin with "it depends." However, I think that 12,000 miles is excessively too soon for rears--and even for the fronts.
Personally, with all other things being equal, I would run from a car that needed new rears after only 12,000 miles. It makes we wonder what else that car was expected to do!
The majority of braking in a 911 is in the front, like most cars. It would seem like you have an imbalanced braking system that has been imbalanced from the start. Perhaps their service manager can explain to you why any 911 would have such a wear pattern.
For my PCCB equipped 2006 car I used about 3% of my front pads after 36,000 miles. And I'm no wimp at applying the brakes--but that's an entirely different system.
Personally, with all other things being equal, I would run from a car that needed new rears after only 12,000 miles. It makes we wonder what else that car was expected to do!
The majority of braking in a 911 is in the front, like most cars. It would seem like you have an imbalanced braking system that has been imbalanced from the start. Perhaps their service manager can explain to you why any 911 would have such a wear pattern.
For my PCCB equipped 2006 car I used about 3% of my front pads after 36,000 miles. And I'm no wimp at applying the brakes--but that's an entirely different system.
12-10-2012, 10:51 PM
#5
As a long time 911 owner, I would first begin with "it depends." However, I think that 12,000 miles is excessively too soon for rears--and even for the fronts.
Personally, with all other things being equal, I would run from a car that needed new rears after only 12,000 miles. It makes we wonder what else that car was expected to do!
The majority of braking in a 911 is in the front, like most cars. It would seem like you have an imbalanced braking system that has been imbalanced from the start. Perhaps their service manager can explain to you why any 911 would have such a wear pattern.
For my PCCB equipped 2006 car I used about 3% of my front pads after 36,000 miles. And I'm no wimp at applying the brakes--but that's an entirely different system.
Personally, with all other things being equal, I would run from a car that needed new rears after only 12,000 miles. It makes we wonder what else that car was expected to do!
The majority of braking in a 911 is in the front, like most cars. It would seem like you have an imbalanced braking system that has been imbalanced from the start. Perhaps their service manager can explain to you why any 911 would have such a wear pattern.
For my PCCB equipped 2006 car I used about 3% of my front pads after 36,000 miles. And I'm no wimp at applying the brakes--but that's an entirely different system.
12-10-2012, 10:54 PM
#7
Racer
Thread Starter
As a long time 911 owner, I would first begin with "it depends." However, I think that 12,000 miles is excessively too soon for rears--and even for the fronts.
Personally, with all other things being equal, I would run from a car that needed new rears after only 12,000 miles. It makes we wonder what else that car was expected to do!
The majority of braking in a 911 is in the front, like most cars. It would seem like you have an imbalanced braking system that has been imbalanced from the start. Perhaps their service manager can explain to you why any 911 would have such a wear pattern.
For my PCCB equipped 2006 car I used about 3% of my front pads after 36,000 miles. And I'm no wimp at applying the brakes--but that's an entirely different system.
Personally, with all other things being equal, I would run from a car that needed new rears after only 12,000 miles. It makes we wonder what else that car was expected to do!
The majority of braking in a 911 is in the front, like most cars. It would seem like you have an imbalanced braking system that has been imbalanced from the start. Perhaps their service manager can explain to you why any 911 would have such a wear pattern.
For my PCCB equipped 2006 car I used about 3% of my front pads after 36,000 miles. And I'm no wimp at applying the brakes--but that's an entirely different system.
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12-10-2012, 11:02 PM
#8
12-10-2012, 11:58 PM
#9
Race Director
Indirectly, yes. My 03 Turbo has over 100K miles on its original brakes.
Contrary to the belief of some the rear brakes of the rear (and mid-engined) Porsche do most certainly play a larger role in stopping the car than in other engine layouts.
This is because the majority of the weight in over the rear axle. Sure under braking there is weight transfer but not as much as with other cars.
This has to be in order for Porsches to deliver their outstanding braking performance. This doesn't arise from the fronts doing all the work while the rears do very little. These cars a very well balanced and this applies to the division for braking between the front and rear axles.
(In the case of the Boxster that the rear brakes play a major role in braking is the presence of brake cooling scoops (those small rectangular things that hang down under the car) which help direct air up and out past the brake hardware.)
If I had to guess, I'd say the excessive rear brake wear is probably do to aggressive driving which results in traction control and EBD (electronic brake differential) activity eating up the brakes.
The car may still be a good car, provided you can determine to your satisfaction the above mentioned aggressive driving has not come about from track time.
The over rev range counters along with engine run time should provide you with some insight. And the car should be inspected for signs of tracking. Bits of tire rubber on the underbody plastic trays and such is a dead giveaway.
Contrary to the belief of some the rear brakes of the rear (and mid-engined) Porsche do most certainly play a larger role in stopping the car than in other engine layouts.
This is because the majority of the weight in over the rear axle. Sure under braking there is weight transfer but not as much as with other cars.
This has to be in order for Porsches to deliver their outstanding braking performance. This doesn't arise from the fronts doing all the work while the rears do very little. These cars a very well balanced and this applies to the division for braking between the front and rear axles.
(In the case of the Boxster that the rear brakes play a major role in braking is the presence of brake cooling scoops (those small rectangular things that hang down under the car) which help direct air up and out past the brake hardware.)
If I had to guess, I'd say the excessive rear brake wear is probably do to aggressive driving which results in traction control and EBD (electronic brake differential) activity eating up the brakes.
The car may still be a good car, provided you can determine to your satisfaction the above mentioned aggressive driving has not come about from track time.
The over rev range counters along with engine run time should provide you with some insight. And the car should be inspected for signs of tracking. Bits of tire rubber on the underbody plastic trays and such is a dead giveaway.
12-11-2012, 02:15 PM
#10
Rennlist Member
If you leave all of the driver aids on and track a car hard for a 3 day weekend it is possible to toast a set of pads. I did it on an 09 Cayman S at Putnam Park.
12-11-2012, 02:49 PM
#11
Burning Brakes
It is doubtful that the rear brakes need replacing but if the CPO warranty is with Porsche they may require new brake pads if less than 50% wear left at the time of the inspection. At least this was the the case when a friend of mine was buying a CPO warranty with Mercedes when his car was three years old but still on the original warranty.
Many manufacturers require every car to go through a thorough inspection and brought to a certain standard before they will CPO. This also includes tires and many other wear items. All deferred maintainance must be brought up to date.
Many manufacturers require every car to go through a thorough inspection and brought to a certain standard before they will CPO. This also includes tires and many other wear items. All deferred maintainance must be brought up to date.
12-11-2012, 05:08 PM
#12
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Brake pads can be changed for issues other than wear. A car left standing in weather can have an effect on the appearance of the pads at their exposed edges, (rusty and crumbled appearance). In an attempt to sell the car and avoid a prospective buyer asking to thave them changed anyway, $300 is not a big price to pay for a good reputation.
And with the types of open wheels normally on these cars, the pads are very exposed and visible.
And with the types of open wheels normally on these cars, the pads are very exposed and visible.
12-12-2012, 02:48 AM
#15
Poseur
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I still maintain that the fronts take the brunt of the effort. Why else have six pistons and a larger caliper up front and only 4 pistons and a smaller caliper out back?