Planet-9 > 987 Discussion Group (Cayman/Boxster) > Cayman and Boxster Tech » Pads & Rotors must be Replaced Together? Yes/No?


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View Poll Results: Pads & Rotors
Pads and Rotors really do need to be replaced together 10 8.13%
Rotors last way longer than pads don't throw away good rotors 113 91.87%
Voters: 123. You may not vote on this poll

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  #1  
Old 01-25-2009, 09:32 AM
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Pads & Rotors must be Replaced Together? Yes/No?

I know there's going to be differing opinion on this subject. That's why I'd love if people responded to the poll.

I've put 35,000 kilometers on my car as a daily driver never tracked.

I'm 2 years into a 4 year lease.

I was told by the dealer I need to replace my front pads and that 'We always replace pads and rotors together (as per Porsche factory recommend.)"

Now I'm guessing my rotors still have some life left in them, but if they're going to be shot by 3 years I might as well do them now since I'd have to do them before I give the car back at the end of the lease.

Just wondering do you guys feel strongly that pads and rotors MUST be replaced together (perhaps so they 'fit' well together when braking with no 'ridges' from previous pads?) or do you think it's nuts to throw away perfectly good rotors with life still in them when all it is is the pads.

Also, one other question. Is it safe to just run my pads down till the warning light comes on the dash? Or do I need to replace them when my dealer says too (like being overly cautious/trying to make a buck.)

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Old 01-25-2009, 09:48 AM
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Re: Pads & Rotors must be Replaced Together? Yes/No?

Pads and rotors do not normally need to be replaced as "sets". Normally, you would simply measure and inspect the rotors, and only replace them if they are close to the wear limit or if they have excessive wear, grooving or cracking.

If you decide to replace the rotors yourself, remember that you will need new caliper mounting bolts -- Porsche says they are "one time use" only.

Originally Posted by hawc View Post
Also, one other question. Is it safe to just run my pads down till the warning light comes on the dash? Or do I need to replace them when my dealer says too (like being overly cautious/trying to make a buck.)
As long as you only drive on the street, and not on the track, you should be safe to run the pads until the warning light comes on. However, if you wait that long, you will then also need to buy new wear sensors in addition to new pads. Normally, I would just replace the pads when they wear close to the sensors, but it's not that big a deal to wait.

Last edited by BillC; 01-25-2009 at 09:54 AM.
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  #3  
Old 01-25-2009, 09:49 AM
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Re: Pads & Rotors must be Replaced Together? Yes/No?

Originally Posted by hawc View Post
I know there's going to be differing opinion on this subject. That's why I'd love if people responded to the poll.

I've put 35,000 kilometers on my car as a daily driver never tracked.

I'm 2 years into a 4 year lease.

I was told by the dealer I need to replace my front pads and that 'We always replace pads and rotors together (as per Porsche factory recommend.)"

Now I'm guessing my rotors still have some life left in them, but if they're going to be shot by 3 years I might as well do them now since I'd have to do them before I give the car back at the end of the lease.

Just wondering do you guys feel strongly that pads and rotors MUST be replaced together (perhaps so they 'fit' well together when braking with no 'ridges' from previous pads?) or do you think it's nuts to throw away perfectly good rotors with life still in them when all it is is the pads.

Also, one other question. Is it safe to just run my pads down till the warning light comes on the dash? Or do I need to replace them when my dealer says too (like being overly cautious/trying to make a buck.)

Up to you on being cautious or not, and following the dealer's advise on when to replace the pads. I replaced mine about 100 miles after the light came on, and looking at it I could see at least another 500 miles of hard driving left on them.


In terms of replacing rotors, I think it's BS... My dealer replaced the front pads without even mentioning anything about rotors (but then they know me)..
But it's not the first time I hear on this board about Porsche dealers insisting on replacing rotors with pads. I mean your rotors COULD WELL BE shot, warped, cracked etc... But if they're healthy, there should be a lot more life left in them after grinding on just one brake pad.
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Old 01-25-2009, 09:56 AM
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Re: Pads & Rotors must be Replaced Together? Yes/No?

Thanks for the replies so far.

I know for sure I'll be buying my parts from Suncoast and then having the work done at an independent Porsche place rather than the dealership.

I think I should have them inspect the rotors before I order the parts.

I was curious because I know in cycling I usually replace my chain and cogs together so they mesh well rather than have an old worn cogs not meshing with a new chain. But who knows.

Wouldn't it be nice if we could actually whole-heartedly trust the dealership and know that they have our best interests at heart? I wouldn't even mind paying more for labour if I knew they weren't gouging me on parts and possibly recommending things that didn't need to be done.

Can you imagine? It would be so refreshing. Ah well.
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Old 01-25-2009, 10:06 AM
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Re: Pads & Rotors must be Replaced Together? Yes/No?

Based on what I read in the service manuals it is not a requirment that the rotors be replaced at the same time as the pads. Rotor replacement is based on specific measurements are a visual inspection. The same holds true with the pads, but they are independent of each other.
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Old 01-25-2009, 10:16 AM
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Re: Pads & Rotors must be Replaced Together? Yes/No?

I'm pretty sure if your rotors are thick enough you can get by with only changing the pads. Of course, you might want to have the old rotors turned--this might make you change your mind if the rotors are only marginally thick. So, no, you don't have to change rotors when you change pads--BUT, it depends on the condition of the rotors.
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Old 01-25-2009, 10:20 AM
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Re: Pads & Rotors must be Replaced Together? Yes/No?

Originally Posted by hawc View Post
Thanks for the replies so far.

I know for sure I'll be buying my parts from Suncoast and then having the work done at an independent Porsche place rather than the dealership.

I think I should have them inspect the rotors before I order the parts.

I was curious because I know in cycling I usually replace my chain and cogs together so they mesh well rather than have an old worn cogs not meshing with a new chain. But who knows.

Wouldn't it be nice if we could actually whole-heartedly trust the dealership and know that they have our best interests at heart? I wouldn't even mind paying more for labour if I knew they weren't gouging me on parts and possibly recommending things that didn't need to be done.

Can you imagine? It would be so refreshing. Ah well.

Can I ask which dealer?
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Old 01-25-2009, 10:30 AM
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Re: Pads & Rotors must be Replaced Together? Yes/No?

Originally Posted by dougc View Post
I'm pretty sure if your rotors are thick enough you can get by with only changing the pads. Of course, you might want to have the old rotors turned--this might make you change your mind if the rotors are only marginally thick. So, no, you don't have to change rotors when you change pads--BUT, it depends on the condition of the rotors.
Since the allowable wear on these rotors is only 2mm from new, it is not possible/advisable to turn these rotors.

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Last edited by beez; 01-25-2009 at 10:34 AM.
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Old 01-25-2009, 10:33 AM
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Re: Pads & Rotors must be Replaced Together? Yes/No?

You know... I get irritated when things arn't called what they are, and lately I hear more and more this called "bill padding"..
It sounds so innocent...soft... and bordering on "accptable"....
"Oh well... dealer padded the bill.. what are you gonna do...."

It ain't no effing "padding"... It's deliberate deception to get into your pocket - the definition of a fraud. Somebody say it.

Yeah yeah, it was just a dealer's recommendation.. Well, I understand dealers don't typically put it to customers this way - Porsche says you don't need pads, I think you do...

And every time they say "we" I would be tempted to clarify is "we" - Porsche AG, PCNA, or Billy Bros, Inc....?

All that said, so far I've been lucky to not end up on receiving end of such ****, which I know will not go well with my type of disposition. My dealer - Holberts, so far has been absolutely professional and accomodating in every respect.

just venting....
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Old 01-25-2009, 11:00 AM
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Re: Pads & Rotors must be Replaced Together? Yes/No?

+1 ....hate being lied to period! never mind insulted.
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Old 01-25-2009, 12:14 PM
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Re: Pads & Rotors must be Replaced Together? Yes/No?

thePurist I completely agree with you, but there is wide disagreement on these things even on this site.

Let me take two recent examples.

My Porsche owner's manual and even a quick call to Porsche North America tells me I need only change my oil every 24,000 kilometers. My dealer (and many, many people on this site say it should be done every 12,000 to 20,000 kilometers.) I'm sorry, but I'll go by what the Porsche factory says.

I get a nail in the middle of my rear tire. I can get it plugged properly and safely for $20 at an independent tire shop or pay $90 to get it plugged at one Porsche dealership (Pfaff) or pay close to $400 for a new tire/install (dealer prices of course) at Downtown Porsche in Toronto. Hmmm.. $20 or $400. In this case Porsche manual says no to plugging a tire, but Pfaff says they've been plugging tires for 20 years without a single failure. I'm comfortable with that track record.

It's like black magic trying to get a straight answer. I guess all you can do is find an independent mechanic you really trust. Not that that's easy either.

Last edited by hawc; 01-25-2009 at 12:17 PM.
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Old 01-25-2009, 12:15 PM
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Re: Pads & Rotors must be Replaced Together? Yes/No?

Originally Posted by shakeypics View Post
Can I ask which dealer?
Downtown Porsche in Toronto recommends replacing pads and rotors at the same time.
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Old 01-25-2009, 12:20 PM
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Re: Pads & Rotors must be Replaced Together? Yes/No?

Oh another one I love.....

Wheels (not tires mind you - just wheels) off and on at Porsche Dealership $90. At Audi $60. At VW $30. In this case all 3 dealeships owned by the same company. I guess they must use special air guns and torque wrenches at Porsche.

So silly all of this really.
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Old 01-25-2009, 12:52 PM
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Re: Pads & Rotors must be Replaced Together? Yes/No?

Originally Posted by hawc View Post



I get a nail in the middle of my rear tire. I can get it plugged properly and safely for $20 at an independent tire shop or pay $90 to get it plugged at one Porsche dealership (Pfaff) or pay close to $400 for a new tire/install (dealer prices of course) at Downtown Porsche in Toronto. Hmmm.. $20 or $400. In this case Porsche manual says no to plugging a tire, but Pfaff says they've been plugging tires for 20 years without a single failure. I'm comfortable with that track record.
Not hi-jackin your post bout pads and rotors but you brought up a somewhat inneresting point I've wondered about. Plugging tires, read you can't, wonder how many have with no issues. And if the dealers had their way it would cost ya $800, not the $400 mentioned as I've read you would need to buy a pair unless there was little wear on the good tire to match up with the new one? I do like the fact that Pfaff does plug if needed.
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Old 01-25-2009, 02:25 PM
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Re: Pads & Rotors must be Replaced Together? Yes/No?

As others have said, rotors don't have to be changed with the pads - but it very much depends on the individual situation. There might be a reason to, if one uses track pads and has punished the rotors a lot, but usually, its not necessary. You should inspect the rotors and see if the wear on them (actual loss of rotor material of 2mm or more, or severe cracking around the holes or connecting the holes) to see if it's required. I'm still on my original rotors after almost three years, 38k miles, probably 25 track days in the advanced/instructor groups, and somewhere near 30 autocrosses. These are pretty darn good good rotors, if you ask me.



Originally Posted by shakeypics View Post
Not hi-jackin your post bout pads and rotors but you brought up a somewhat inneresting point I've wondered about. Plugging tires, read you can't, wonder how many have with no issues. And if the dealers had their way it would cost ya $800, not the $400 mentioned as I've read you would need to buy a pair unless there was little wear on the good tire to match up with the new one? I do like the fact that Pfaff does plug if needed.
On patching tires... Yes, it's safer to replace the tire, and technically, the speed rating is lost on a tire that's repaired. That's not to say you can't patch tires and be fine for normal street driving. But, if you are prone to pushing the limits of the car, either on the street or on the track, a repaired tire can be a safety liability to yourself and those on the road around you. If I were driving on a plugged/patched tire, I would not push the car anywhere near it's lateral force or top speed limits. With that in mind, repaired tires do work for some folks.

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Old 01-25-2009, 03:00 PM
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Re: Pads & Rotors must be Replaced Together? Yes/No?

Replacing pads doesn't mean you need to replace rotors,however replacing rotors usually, but not always, means you should replace pads.
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Old 01-25-2009, 03:18 PM
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Re: Pads & Rotors must be Replaced Together? Yes/No?

Never replaced rotors because new pads, in 30 years with any of my cars. My new Porsche is not going to be the exception. Also, never I have let any monkey turn my rotors either! It just doesn't make any sense (to me) to take away good metal. They worked fine with tiny little groves just before? It seems to me that these things have to be over-engineered by nature and there is a big safety margin in the design. It is a personal decision, how far to push the limit.
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Old 01-25-2009, 04:05 PM
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Re: Pads & Rotors must be Replaced Together? Yes/No?

My Porsche owner's manual and even a quick call to Porsche North America tells me I need only change my oil every 24,000 kilometers. My dealer (and many, many people on this site say it should be done every 12,000 to 20,000 kilometers.) I'm sorry, but I'll go by what the Porsche factory says.

This is the same issue I raised earlier last week. Why do the dealers say every 12 months for an oil change when the manual indicates 24 months. They just want you hard earned money!!

My complaint was my Service Now indicator came on prematurely at exactly 1 year. According to the manual it should have come on at 24 months or at 20K. Again dealer mischief!
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Old 01-25-2009, 04:08 PM
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Re: Pads & Rotors must be Replaced Together? Yes/No?

I forgot to mention, when I had my 05 Boxster, I had the the rear tires plugged twice for $12.00 at a service station. I never had any problems at all whith the the tires or the plugs thereafter. I do not track my car, it is simply for driving pleasure.
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Old 01-25-2009, 04:08 PM
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Re: Pads & Rotors must be Replaced Together? Yes/No?

The rotor pad case is very much an "it depends" situation, and the current day auto repair business (dealers and independents) can't seem to deal with "it depends", so we get these binary rules.

In an ideal world it really is a good idea to replace the rotors and the pads as a set. Rotors almost always develop grooves, and some pads, especially low-dust pads, can dig some pretty deep grooves. You can machine away the grooves by turning the rotors, but the advent of vented rotors has made turning nearly obsolete. Vented rotors are sort of like two rotors in one, but each only about 1/3 as thick as the rotor itself, making them pretty thin. Machine away 2-3mm of metal and what's left may warp from heat, spawning "comebacks" from the brake pulsing that results.

I think many of us have replaced the pads without replacing rotors or machining the old rotors, and had no problems. I've probably done it fifteen times over the years (maybe more) and I had a problem twice. Both times on BMWs,with those massive single-piston calipers they use. The new pads squealed like baby pigs, and the only cure was new pads and rotors. That's right, once you groove the pads with old rotors you're done, you gotta buy new pads. Squealing happens, and most people hate it, and the only practical cure is a redo of the brake job. So, what do we get? Rules that say no pads changes without new rotors.

I'm actually pretty thrilled that my CS rotors are showing no wear or grooving at all after 5700 miles. No cracks either. My Benz rotors are shot after 20K miles, and I have a manual trans car. The automatic versions often eat rotors & pads after 10K miles, and, BTW, they're essentially the same brakes as in the CS.

Tire repairs are in a similar state of disarray. I've been plugging my own tires for years, even runflats, and I've never had a problem. Not even one leaker. Zillions of independents repair some tires, but not others. Then there's Porsche. No repairs. You can't even mix N-specs. Expensive? Too bad. It's a Porsche. I love it.

I know some people like to blame attorneys for all of this, and perhaps they play a role, but this lack of risk-taking by repair shops and dealers is OUR fault, IMHO. The mentality that a repair must be perfect the first time and forever or the shop is incompetent is the cause of all of this ***-covering behavior. That's another reason I to do my own work. Then I know who the incompetent mechanic is and where to find him.

Last edited by blueone; 01-25-2009 at 06:12 PM.
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