gota911

Macster,

I bought the one year old CPO car with 2,945 miles on it from a Porsche dealer. I believe my rotors are the original factory rotors and have not reason to think otherwise.

However, I think you make a good point about the potential of a "softer" rotor on the right side. The right front rotor does have a slightly larger lip on it than the left front rotor has.

The excess amount of brake dust on only one wheel does bother me a decent amount, hence this thread. If I am going to do a thorough inspection of the pads and rotors, I might as well change to rotors "while I am in there."

My Hawk Performance Ceramic Pads have about 11,000 miles of use on them. If I change the rotors, would you also changing the pads? The excess brake dust on the right wheel was also present when the original OEM pads were on the car, but much worse, as would be expected with the OEM pads.

Lugs H

This is a wild guess but consider this. You have radiator fans on both sides that exhaust into the wheel well. When they cycle on it could, not saying that it does, blow brake dust on to the wheel. What if your left one is not working and the result is less dust on left compared to right.

Petza914

I totally get the "I can't do this to my DD as I could strand myself" - maybe rent a car for a weekend and do it so you'll have a back-up. Be sure you don't run the resevoir dry or you'll likely need a Durametric to actuate the ABS pumps to get all the air back out of the lines - ask me how I know :-/

If you do decide to change out the rotors, we put a set of 2-piece dba 5000 series slotted rotors on my wife's 997.1 C2S that have been great. The other advantage to piece with the aluminum hats, aside from the lighter weight, is that you eliminate the ugly rusty rotor hub and vanes issue when the wimpy silver coating wears off on the Zimmerman's or Sebro rotors.

Here's a photo from when I installed them as she was repainting her big red calipers white to better go with her pink pearl 911. Brakes are spotless - car is filthy in the photos - sorry. Also had heat resistant vinyl decals made in her girly font to tie it all together. Not everyone's cup of tea, but she loves it, which is really all that matters. I have the PCCBs on mine so don't really have any dust or rust issues to deal with, which is almost worth the price of admission by itself.

Rotors came from www.TopBrakes.com (http://topbrakes.com/c/car-series/44...cast+iron+disc) as a front left & right pair for a special price which was about double OEM replacements, but from here we can just replace the discs themselves, reusing the hats, which will make it less expensive in the future. They make a 1-piece 4000 series too, but with the special pricing on the 5000 series, oddly, those are less expensive. They also have the black e-coat for the center so the vanes don't rust over time either, and as a plus have temperature paint lines so if you track the car or drive it spiritedly, you can see the rotor temperature by looking at the paint lines.

I don't know if the gen 2 cars use the same size rotor with the same offset or not, so check into that prior if you're going to go that route. I have the Hawk HPS pads paired with these and they're a good combo between braking power and low dust. I would do new pads if you do the new rotors just so they bed in together properly. The other advantage to slotted over drilled or drilled & slotted is that you still get very good wet weather performance, but don't get the hairline cracks around the holes if you use them for some track days - the rotors without the holes are more stable and provide a better heat sink since there's more material.

Keep us posted on what you decide to do and the results.

gota911

All of this is good info guys! Too many variables, so many possible causes. Nothing is ever simple, especially on a Porsche.

I'll see if anyone else chimes in with any other ideas to make it even more complicated!

altonj

I read most of thread, but maybe missed a critical part.... Lets recap and start from scratch...

You only are suspicious of a problem because of more brake dust on one side vs the other?

The caliper on the "dirty side" was replaced? If i read correctly your dealer replaced the caliper that was creating more pad dust? If you have a caliper issue, your dealer may have replaced the wrong one...

Are experiencing any driving issues?
Does the car pull to the right under hard braking?

Cheers

stronbl

60,300 miles on the brake discs seem on the high side to me, but I don't know your driving/braking style so you could be ok. Minimum brake disc thickness is 32.0mm on front discs (wear limit) - assuming iron discs. Also you measure 3 points in a triangular shape (centered on the wheel hub) on the inner or outer edge (not the center). You should also observe any small cracks from the cross drilled holes. Any exceeding 7mm indicates the discs should be replaced. Cracks running to the edge of the disc suggest disc should be replaced too.

If you try the piston test I mentioned it will indicate issues with fluid movement through the system. You cannot truly compare right caliper to left caliper in this test, but you can compare inner versus outer piston in the same caliper. How much the piston extrudes will give an indication of fluid flow within that caliper. Just remember one pump only, you do not want to push the piston too far, just enough to see the behavior. If in doubt, don't do the test - I take your point about the car being your DD.

I am not 100% certain but I believe on 997-2, including MY 2010, Carrera S and 4S had metal woven or braided inner tubing in the brake caliper hoses. Brake line problems could be part of the problem but I think it would have to be a rather serious kink and clearly visible.

Lastly I was thinking a bit more about your issue and another idea is that the wheel hub itself may be the culprit (i.e. where the brake disc attaches). If this hub is dirty or uneven in some fashion, it will cause the brake disc to be attached also in an uneven manner and thus cause an uneven lateral run-out on the disc. In other words you will see or feel undulations radially outward from the wheel hub center to the brake disc edge, potentially causing greater brake pad wear and/or dust. The remedy would be to correct the hub unevenness and replace the front brake discs (always replace both discs as a set), ideally with new brake pads too.

gota911

I had brought this issue to the SM's attention on two different occasions and they could not determine why the extra brake dust on the front right. They did see an extreme example of the brake dust prior to the 3rd visit and both service managers agreed it was excessive. The tech doing some minir warrnanty work replaced the caliper, the correct caliper. The caliper change did not help reduce the brake dust.

I have not experienced any driving issues. The car does not pull to the right under hard braking, which makes this issue all the more puzzling. The only symptom is the excessive brake dust.

gota911

I have decided to replace the front brake rotors and pads. The rotors would probably need replacing in the next 10K miles anyway, so I might as well do it now. I will also visually check the brake lines while I have the wheels off.

I will let you know when the parts have been replaced , which probably will not occur until Saturday, March 7. If ,at that time, I aam feeling like "living on the edge," I may test the amount of piston movement as stronbl has suggested. But don't hold you breath on that one.

Once the parts are replaced will begin to moniter the relative amount of brake dust, "old" versus "new" parts.

Thanks to all of you for the insight and comments. I really do appreciate everyone's input.

gota911

OK, it has been about 2-1/2 weeks since my last post in this thread, so I thought I would give an update on my attempts to eliminate the cause for the excess brake dust on the fight front wheel.

I installed new front rotors and front Hawk ceramic pads last evening. The previous Hawk pads showed little wear and could have easily been reused, but I changed them out anyway.

Here are pics of the two original rotors. The right rotor (1st pic) was definitely more worn that the left one, which I expected because of the additional brake dust on the right front wheel. The second pic is the left front rotor. IF you compare to two inner (smaller) wear dimples the one on the right rotor is smaller that the one on the left rotor.

I'll monitor the brake dust over the next few weeks and see how the two sides compare in relative brake dust. More to come later.

Thanks again for everyone's input.