Another noob thread....

Ladies and Gents, I've searched the threads, but haven't found any info to help me with my questions below so here goes. * According to my PPI my '03 C4 has 50% brake wear that I bought in mid July. Yesterday I was driving around when the "brake wear" light came on. At what point does this light come on? I live in PA and have an inspection this week. I assume that even though the light came on I will still pass inspection, but what gives??? * Depending upon the weather I tend to accumulate a good amount of condensation on the windshield. Is there a way to minimize this? Its annoying at best and dangerous at worst. * Tail lights - I plan on replacing my tail lights and have seen brands like Del Rey and Spyder. Are there any other recommendations? Any one brand tend to be preferred to any others?

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You have wear sensors on each pad and when the pad wear down to the sensor, it creates a short to alerts you. No worries you'll still have braking, but you need to change out your rotors and pads asap. Also, you'll need to replace the sensors too. I live in Georgia and our climate is very hot and humid, and that means lots of condensation build up. Fortunately, my 996's A/C works great to minimize this effect by selecting the defrost/dehumidify button. But I've heard many stories how a failing AC can not eliminate it in some climates.

To add to b3freak's excellent post let me add the sensor is about 3/16" in diameter. Thus nominally there is 3/16" pad material left on the pad that wore down enough to trigger the light. However, the pad may not be wearing evenly so while the pad thickness is 3/16" at the sensor which is located in the middle of the pad the thinnest part of the pad may have less material. You should arrange to replace the pads, rotors, and sensors very soon. BTW, budget for a brake (and if your car is a manual a clutch) fluid flush/bleed. This is due every 2 years and my experience is letting it go even 6 months past this results in clutch (and shifting) problems. For those who live/drive in humid climes it is advisable to a few miles/minutes before putting the car away for the day/night to shut off the A/C -- turn off the snowflake symbol -- and leave the cabin vent fan running. This helps dry out the moisture that has condensed on the interior surfaces of the A/C system. If this is not done as the car sits and heat soaks moisture will flow with air up to the glass and condense on the inside. And when the engine is started the next day the interior glass surfaces can fog. This lack of drying can encourage mold/mildew to take root (so to speak) in the A/C system on the evaporator or in the catch tray under it and then the system emits a foul odor that is hard to eradicate. The cabin air filter element can develop an off odor too over time but this is "fixed" by periodic replacement of the filter element. Also, be very sure the body water drains are free of trash build up and are letting the water (from rain or washing) drain with no hinderance. And last but not least, while this won't effect the interior of the car directly, be sure the radiator ducts are free of trash build up too. If you run the A/C the radiator fans run all the time and with these running the car is just one big old hoover vacuum clean the radiator fans sucking in all kinds of (mostly) plant trash. The radiator ducts require periodic cleaning.

^^^Wow, you thought of everything Mac! Great write up!

New brake pads yes...rotors too? Unless the rotors have a good lip to them I say leave them alone. Rotors last way longer then pads. If you want to get past your inspection with out replacing the pads pull the sensors out of the pads and zip tie them to a suspension part.

One additional point about the climate control - some owners have never realized that if you press the climate control button with the icon that looks like a dash vent, this causes most of the air to be discharged through the dash vents. If this is NOT selected, much more air will be discharged through the dash; if you're in a humid location, this will fog up your windshield in short order.

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Oh, I thought that was the CD eject button. No wonder it didn't work. Dab nabbit, now I should've kept my OEM Stereo.

I would be annoyed that a 2 month old PPI said I have 50% break wear. Sounds like they may have only checked one wheel rather than all four OR just gave you some BS answer.

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^ I take any "professional" estimate about brake wear, tire pressure, etc. with a grain of salt. My wife took her SUV into the dealership - they advised her that her rear brakes were 85% gone (i.e. in urgent need of service) and noted different PSI figures for all five tires (four plus a spare). The rear pads were new - barely even bedded. At least 95% pad remaining, but the real rub was that her X5 had run-flats; there WAS no spare tire. I don't mind the brake life "estimates" as much as the outright lying about the tire pressures (if the tech lied about checking the spare, what are the odds he bothered to check the four tires that were actually present?). A customer relying on those numbers as fact and then having an accident due to tire failure would cost more than one job, a fact the service writer seemed unconcerned with when I pointed out the fictitious tire pressures. Anyway, those brake estimates are just estimates - but they are usually TERRIBLE estimates. Heh - you think I'm kidding? There is at least one thread here with an OP complaining that there should be class-action against Porsche for the windshield fogging - until someone pointed out to OP that he did not have the dash vents on.

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I've seen the complaints many times... I guess they think "AUTO" really means "all knowing".

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Yep. I'm on the tech inspection team, and at each event we have to crank through inspecting roughly 100 cars in an hour and a half. I've seen two different people give vastly different estimates of tread wear and brake wear on the same car. We are mainly concerned with whether there is sufficient tread and pad left to be safe, so as long as both estimates are in the "thumbs up" territory all is good.

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Don't get spyder. Check my thread from today. Nightmare

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That mechanic's bad estimate may cost me tomorrow. If I had known the brakes were that shady I would've negotiated the cost even further. That is a legit expense. whatever...

Assuming you didn't put 2K miles of alpine driving on the car, it sure sounds like they got the brake wear wrong - but if all the car needs is pads on one end, your exposure for materials is a hundred bucks. Brakes on the 986/996 platform are ridiculously easy. It takes longer to jack the car up and remove two wheels than it does to remove and replace brake pads. Some of us who handle our own brake maintenance also remove the wear sensors from the pads and zip tie them to the brake line or other handy spot. If you're NOT doing your own maintenance and regularly checking brake material, leaving them installed and replacing the one(s) that get ruined when the brakes are nearing end-of-life is probably your best bet.

* You may have one sticky brake piston which is dragging slightly when driving. This will wear the pads down quicker on one rotor. Need to remove wheels and visually inspect. Another vote for pads yes, rotors on condition. A brake rotor will typically go 3-4 sets of pads provided it's not overheated. Again - this ONLY means on condition. There is a min thickness for every rotor. Find that number and have yours checked. Rotors can also be turned if there is uneven wear, but don't turn them under min thickness. *Condensation on the windshield means there is moisture getting into the car. Either from evaporation, or a leak. Check the sun roof seal, and carefully the side window seals. I found a leak around the lower left window seal that would let in rain under heavy conditions. * Don't know, can't help.

Is there a way to test your brake pistons and determine if they need to be serviced?

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More times than not, your dust boot seals will go bad first. If you have torn or burnt dust boots, I'd definitely inspect your pistons and seals for any wear or pitting and/or leaking. To really inspect it, you'll need remove the calipers and out a block of wood between the pistons and run compressed air to the line to expand the pistons. See if you can push each one back little force to make sure one isn't sticking. You can go further by removing the dust boots and expanding the pistons again and removing each piston to visually inspect them and the seals. In my experience I've rarely had any modern brake systems fail. Usually the dust boots will get brittle and start cracking off if you track it a lot and are heavy on the brakes, but the pistons and seals do fine since they are bathed in brake fluid. A lot of the higher end cars uses SS piston cups too where as the older cars, you have to worry about rusting issues and piston seizing if sitting around for a long time.

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There is no metric or calibrated pressure test that I can think of to check for piston sticking in the bore. Visually inspect the boot, and look at the edge of the piston for scoring or rust. If you find anything, disassemble the caliper and see about replacing the damaged stuff. Brake pistons are very, very robust as are the cup seals because a bad piston can be catastrophic and cause an accident. However, due to dust, and some enviro conditions, it can start dragging and heat the rotor which causes pad wear. Look for uneven pad wear across the face in calipers where there are more than two pistons(one per side), which would indicate one of the pistons is sticking.