Brake job: does it matter where?

[rteichman]

I need to have the front brakes on my 99 Boxster replaced. How bad would it be to go to a Midas or Generic Tire place (the one that had the latest and greatest Hunter equipment for balancing/alignment) to do the job? I know the good Porsche mechanics in my area but they work mon-fri and I need to have work done on a Saturday. If you guys think its ok to use a non-Porsche specialist, then my next question is should I get the brake fluid changed at the same time (it needs it) or should I wait for a time when I can get it into a specialist (about 3 months from now)

I would not go to a Midas or generic place. But, that's just me.

If you are a little handy, these are DIY projects, and there are great threads on this forum to walk you through the proper steps.

You need to change your brake fluid every 2 years.

Buy your parts at a place like www.sunsetporsche.com or www.suncoastporsche.com.

[RandallNeighbour]

My mechanic says flush the brake fluid out every time you put pads and/or pads and rotors on the car. It's not terribly expensive stuff, and it keeps the car safe to drive at high speeds.

I would agree that you should not let Midas or another chain do a brake job on your boxster. While it's actually quite simple to change the pads, requiring simple hand tools and a jack, the employees and managers of these chains have no familiarity with the car, and therefore, will be experimenting on YOUR baby when you bring it in. That's not a risk I would personally take!

Find a good independent Porsche mechanic and arrange to drop the car off on a Thursday night and get a lift to work while they do your brakes on Friday. Pads take about an hour total.

PS - Just as an FYI, the brake discs are usually changed out every other pad change... and Porsche does not recommend turning them (grinding down the grooves). I do hope yours aren't worn too thin! Mine are just about gone and will have to be replaced at the end of this year I'm guessing.

[denverpete]

Originally Posted by RandallNeighbour

PS - Just as an FYI, the brake discs are usually changed out every other pad change... and Porsche does not recommend turning them (grinding down the grooves). I do hope yours aren't worn too thin! Mine are just about gone and will have to be replaced at the end of this year I'm guessing.

Randall -

After replacing so many parts on your Boxster - is it now considered "new"? I'd love to see a thread or something where you list everything you've done.

Appreciate the advice on the brakes.

[Brucelee]

"PS - Just as an FYI, the brake discs are usually changed out every other pad change... and Porsche does not recommend turning them (grinding down the grooves). I do hope yours aren't worn too thin! Mine are just about gone and will have to be replaced at the end of this year I'm guessing.""


If you go to an honest and competent brake guy, he will MEASURE the thickness of the rotor. The last time I did brakes on a box, the rotor COULD be cut and we did, saving TONS of money.

However, without measuring, you can't know for sure if this is safe, ie, will the rotor be up to spec after cutting.

Good luck!

[RandallNeighbour]

Originally Posted by denverpete

After replacing so many parts on your Boxster - is it now considered "new"? I'd love to see a thread or something where you list everything you've done.

Well, I have replaced a lot of stuff on the car, but I wouldn't say it's new by a long shot... most of the suspension is original except for one front control arm and two rear struts. The drive shafts, exhaust, cats, A/C, and radiators are all original too.

But, with time all these will go out too and I get to replace them. Yeah!

You can see what I've replaced and the mods I've done by visiting the web site I set up before I bought the car... http://www.iwantaporsche.net

Feel free to donate a couple of bucks to my supercharger project while you're there. There's a paypal link at the bottom (there should be no doubt that I am a preacher and have no problem asking strangers for donations!)

[PorscheDoc]

I would find an independent porsche/audi/volkswagen shop or take it to the dealer. With that being said though, the brakes on a porsche are so incredibly easy to change it isn't funny (Most domestic cars are much more involved). Anyone with an clue of how a screw driver and a pair of pliers work, can change out the pads and rotors, especially if they have done brake work before. Problem with taking it to midas, is they will probably use a knock off pad and rotor instead of brembo/pagid, etc. They also will not install pads and rotors if you bring them with you (they make their money in selling the parts).

[MNBoxster]

Hi,

Brake Repair is not Rocket Science, it's all very straightforward. But, there are several things you need do properly.

You want the proper Pads. There are lots of Aftermarket Pads which will fit, but really should not be used. If not using OEM Pads, you need to be certain the dimensions are corect. Thickness varies widely among Aftermarket Pads. The correct dimensions are: 12.0mm (0.47') for the Front Pads and 10.5mm (0.41') for the Rears (Standard and 'S' Models). The allowable wear dimension is 2mm (0.08') for both (this is slighty more than the thickness of a Quarter). Also, too agressive a Pad will quickly wear the rotors, often at a rate faster than the Pads themselves. This is problematic because Brake wear and the need for attention is often determined by the Brake Pad thickness. Also plan to replace the Vibration Dampers at the same time as the Pads are changed and use a File to Champfer the Leading Edge of the Pad Material to a 45° angle to insure proper Bedding and Full Facing of the Pads.

For Rotors, these need to be checked for thickness using a Micrometer. New Rotors measure 24mm (0.94') (28mm (1.1') for 'S' Model) for the Fronts, and 20mm(0.79') (24mm(0.94') for 'S' Model) for the Rears.

The Wear Limit is 22.6mm (0.89') (26.0mm (1.02') for 'S' Model) for the Fronts, and 18.6mm (0.71') (22.0mm (0.86') for 'S' Model) for the Rears.

The Rotors should also be checked for Lateral Runout (warping) using a Dial Indicator. This is very important. Maximum allowable Lateral Runout is 0.03mm (0.0011') for the Rotor alone and 0.06mm (0.0023') with the Rotor Installed (adding in allowable Hub Lateral Runout of 0.03mm (0.0011'). This is important for both proper Pad Wear and reducing/eliminating Vibration in the Brakes.

These tolerances are so tight that Machining is generally not recommended. This is because these tolerances approach the accuracy limits of most Brake Lathes and when trying to eliminate the Lateral Runout - the most important function of machining, you can easily exceed the overall allowable thickness dimension. In either case, there will invariably be a trade-off between Lateral Runout and Thickness.

Also, NEVER use, or allow a Shop to use a Pneumatic Impact Wrench when installing your Wheels. This is because these tools are notoriously inaccurate and inconsistent with the amount of Torque they apply. Today's Rotors are much less massive than years past in an attempt to reduce both Overall and Unsprung Weight. Improper Torqueing of the Wheels Lugs will cause the Rotors to Warp. If using a Shop, do not just insist that the Wheel Lugs be tightened by hand using a proper Torque Wrench, actually Watch them do it!

In addition, before pressing the Caliper Pistons back into the Calipers, these should be inspected for corrosion and if present, the Calipers should be rebuilt. Failure to do this will result in the corroded Pistons Tearing the Caliper Seals and loss of Brake Pressure and Fluid Leaks. Also, the Dust Seals around the Pistons should be checked at the same time.

Flushing the Brake Fluid is also recommended as it will most probably have been in the system for two years or more. There is a different procedure for doing this depending upon if your Car is equipped with PSM/TC or not, so be sure you know the difference.

Finally, it's very important to properly Bed-In your new Pads. If you're not aware of this procedure, search for my thread detailing the proper procedure for doing this. Hope this helps...

Happy Motoring!... Jim'99

[rteichman]

Originally Posted by RandallNeighbour

drop the car off on a Thursday night and get a lift to work while they do your brakes on Friday

I am only "home" from Friday 7pm to Monday 6am, and the Porsche specialists are all in bad areas where I would not want to leave the car out overnight. Thus until I am "back" home for a week I need to do it at a place that is open on Saturday. Also, with my limited time at home, I rather not spend my weekend working on the car.

[RandallNeighbour]

Sounds like you've painted yourself into a corner with your rigid schedule and you'll have to figure out how to fix on your own. Lots of luck and let us all know how you made it work.

[rteichman]

Well the same job imposes the rigid schedule gave me the extra disposable income to purchase the Boxster in the first place. So I guess I can't complain

Originally Posted by RandallNeighbour

Sounds like you've painted yourself into a corner with your rigid schedule

[RandallNeighbour]

Can you take a day of vacation and schedule the brake job in advance? You do get vacation days with this demanding job, don't you?

I'm working for you here, friend!

Can't the repair facilty give you a loaner car? Maybe this is the added value that a dealership repair can afford you.