30% on break pads - replace before Fontana DE?

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30% on break pads - replace before Fontana DE?

Postby amnons on Mon Mar 07, 2011 10:08 am

Can use some advice from experienced club members ...
I have 30% left on my break pads, (both front and rear), and I'm driving to Fontana this Friday for a fun DE.
My car is complety stock.
Should I get new break pads beforehend?
Thanks,
Amnon
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Re: 30% on break pads - replace before Fontana DE?

Postby mrondeau on Mon Mar 07, 2011 10:31 am

YES!!!!! You do not want to run out of brake pads while at the event. I'm also assuming that you are going to be driving home and will probably need to use your brakes once or twice on the way home.
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Re: 30% on break pads - replace before Fontana DE?

Postby Cajundaddy on Mon Mar 07, 2011 11:14 am

+100!! Bed in some fresh pads all around and throw those "almost gones" in your spares kit just in case you have a brake pad issue some day. Also make sure your brake fluid is fresh. :rockon:
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Re: 30% on break pads - replace before Fontana DE?

Postby Kim Crosser on Mon Mar 07, 2011 12:51 pm

And in case no one mentioned it... John Rickard explained to me that you do NOT want to put in fresh pads and immediately go out on a track. The new pads need to be through some moderate heat cycles (some freeway and street driving for a day or so) before the high heat cycling on the track, or you could discover that some of the compound in the pads has melted into a soft goo, which is now all over your rotors and suspension parts. Apparently there is some "curing" (aka "bedding in") that the adhesive needs to undergo during the initial heat cycles, but if you overcook them too soon, bad stuff happens.
TireRack has an article on properly "bedding in" your new brakes - some pads recommend up to 500 miles of normal driving to get the pads properly bedded in (with notes that "heavy braking should be avoided during this period").
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Re: 30% on break pads - replace before Fontana DE?

Postby Jad on Mon Mar 07, 2011 12:55 pm

I know these are not the answers you wanted, but you also will need the extra material of new pads to help cool the brakes at a DE. Keep the old parts for an emergency or for the other guy that wasn't smart enough to change them before hand. You can be a hero!
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Re: 30% on break pads - replace before Fontana DE?

Postby amnons on Mon Mar 07, 2011 3:50 pm

Thanks, everybody, your replies are VERY clear and informative.
Kim, I had no idea bout the 'break - in" of breaks :). Thanks. As I will be driving up on Friday, that may take care of it.

As I have never done breaks myself, I called our friendly Porsche dealers to get an idea, and got some confusing information:

Pioneer said that typically the rear break pads wear slower and they start off thinner anyway, so, in all likelihood, I will only need the front breaks done. And probably no rotors.
This runs about $750.

Hoehn said that 99% of the time rotors are also required, and that runs about $1200 per axle + $200 for break fluid flush.

Does that sound reasonable? I naively thought that this kind of job should be cheaper. but then again, it is my first Porsche ...

Should I find a way to measure myself and compare to specifications? The 30% number is what I got when I went through tech for PDS.
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Re: 30% on break pads - replace before Fontana DE?

Postby Cajundaddy on Mon Mar 07, 2011 4:49 pm

A quality set of pads is about $250 per axle and if you can jack up your car and change a tire you can change your front pads yourself in about an hour. One of the easiest DIY jobs on a Boxster. My rule of thumb is if the pad material is <= the metal backing thickness they are done. A quick look with a flashlight will confirm this. I measure my rotor thickness and usually change rotors every other set of pads. Minimum rotor thickness is usually stamped on the rotor hat. Whatever you do, get it done soon and put some mileage on your car so your brakes are well bedded before track day. Several moderate heat cycles is best for complete bedding.
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Re: 30% on break pads - replace before Fontana DE?

Postby Kim Crosser on Mon Mar 07, 2011 6:11 pm

Forgot to add the link to Tire Rack article on brakes: http://www.tirerack.com/brakes/tech/techpage.jsp?techid=85

Note that there are different recommended methods for bedding-in for different brake brands. Just driving around isn't necessarily the best way to do it.
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Re: 30% on break pads - replace before Fontana DE?

Postby Steve Grosekemper on Mon Mar 07, 2011 6:41 pm

Amnon,

You really need to know how much brake pad you have left.
The tech inspector was looking through a wheel with questionable lighting...
What 30% means is "get them checked".

Now to answer your questions:
-Fronts always wear out faster
On a gently driven street car the rotors wear more during the life of the pads than a car that is tracked.
For example your pads start at 10mm and should not be used below 4mm at the track (Light goes on around 2mm)
Your rotor thickness difference between new and old is 2mm. So if you wear 1.4mm off on one set of pads you sould replace the rotors because they will be 1mm undersized when you are 50% down on your second set of brake pads.
On the track pads wear faster than rotors. A dedicated track boxster may get 2-3 sets of pads out of a set of rotors.
Changing pad complound is a tricky thing and should be well researched first... Cost/quiet/better stopping. Pick what percentage of each you want because you can't have them all.

As far as brake fluid goes it needs to be checked with an electronic brake fluid tester to measure the percentage of moisture in the fluid. Then you will know if it needs replacement of not.

Most shops want to replace pads and rotors as it keeps the brake noise down and complaints from drivers.

That all being said... I am doing some pre-tech inspections this week and if you come by the shop Tuesday or Wednesday (But not Thursday) we can measure and inspect the brakes in the course of doing the inspection.

Please send me an email for an appointment time if you would like top do this.
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Re: 30% on break pads - replace before Fontana DE?

Postby gulf911 on Tue Mar 08, 2011 12:50 am

amnons wrote:,

Pioneer said that typically the rear break pads wear slower and they start off thinner anyway, so, in all likelihood, I will only need the front breaks done. And probably no rotors.
This runs about $750.

.

750 to replace front pads and no rotors?? :banghead: I am in the wrong business....
Check out google for you tube video of the whole process. And complete step by step articles
If you can change a tire you can do this. $250 for pads so thats $500 for labor, for about an hours work, maybe...
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Re: 30% on break pads - replace before Fontana DE?

Postby martinreinhardt on Tue Mar 08, 2011 10:51 am

Amnon,

I'd recommend to bring your car to Steve to get it checked and maybe also have him replace the brake fluid with ATE Racing Racing Blue if you track the car. You can't go wrong with Dieter's Motorsports, MirageIntl, Black Forest or RSR Motorsports, it will cost you less and the work will be done right and for your needs. Plus they all race and most likely will be at the tracks too if you need some help or advice.

Personally, I don't use official dealers (Pioneer or Hoehn etc.) for anything other than warranty repairs and reprograming my car to disable features or maybe to buy a brand new car. If I need parts I'll buy them out of state online and install them myself or have one of the above do the work if it's over my head.

Have fun at the Fontana
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Re: 30% on break pads - replace before Fontana DE?

Postby amnons on Thu Mar 10, 2011 4:30 pm

Thanks again, everybody, for the great information, advice and help.
I have learned more about breaks then I even knew before.

Anyway, I went to Jay (Mirage Intl.), who is really close to my workplace. Following his inspection, he replaced my front pads (rears are okay) with factory pads. These seem to be a good compromise for me, as I drive my car roughly 50% on the road and 50% AX and DE. Next time I may also replace my break fluid, too late now.

Jay's price was very fair, great service too, no surprise here.
Oh, yes, he also tech inspected my car :)

I am ready for tomorrow, did one short heat cycle this morning and it is another beautiful day in San Diego.
Life is good.

Maybe I will follow Kim's advice from now on: "breaks just slow you down ..."
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