Front brake discs at 1.4 mil,should i change?
 

I have a 06 boxster s with 92000 kilometers (55000 mls) and pads are almost
gone,maybe 4mil left.Measured rotors and get 26.6 mil both sides,(28mil new,26 min wear) no stress cracks around holes and otherwise look really good.Should i just install another set off pads and run it or should i do rotors also,i figure thease are the original rotors and probably 2nd set off pads but not sure as iam not the original owner but it is all porsche stuff (no after market) I only use car as a daily driver,no track ect..

The brakes are THE most important safety system on the car. The fact that you can even ask the question, frankly, indicates that you haven't thought this through. You should ALWAYS replace the rotors when you replace the pads, and you should do the homework to make sure that both items are OEM or better quality. Period.

Your rotors are still well within factory spec so on a street car that does not see excessive brake heat, a pad replacement only is SOP. If you do a lot of track work and need ALL of the brake heat management you can get, replace the rotors too. As long as rotor thickness is not below minimum runout, they are still serviceable.

The rules for brakes are simple.

If the rotor is within spec, have it resurfaced, and change the pads

If the rotor is out of spec, replace the rotor.

Use high quality pads.

I wouldn't worry about resurfacing the rotors as that will put you too close to the minimum and unless they're vibrating at highway speed applications, it's unnecessary. The new pads will wear into the rotors.

Some varying thoughts expressed here on how far to push brake parts. If this was my car (also a DD) I would replace the rotors, my reasoning being that, even though they are within spec now, the next time you come to replace the worn pads they will definitely be worn past min spec and you will have been running them that way for some time as you probably will not replace the pads again until they are completely worn down. Resurfacing is not an option as these are drilled rotors we are looking at.

I'd have to agree, for the most part, with Welles. Brakes are not the component to try and cheap out on. I'm always amazed that some people are willing to spend big bucks on fancy Techart wheels but don't want to spends a couple of hundred on something actually important, like brakes.

The pads appear to be lasting approx 50000 kilometers per,I have already purchased the porsche pads but not rotors ,there is definately no warpage at hwy speed and no hairline cracks near the holes.Based on the spec info i have given how much more wear will the rotors see before the next set of pads is toast,don,t have a problem changing the rotors out but not if i think i may be able to wear another set off pads on them.If my pads last 50000 kilometers that means i will have approx 90000 miles on the rotors,is that possible.

It all depends on driving style. I can drive the 9 mile back road I live on with out braking at all if not forced to by obstacles or other motorists. If you're gentle, rotors could certainly last through 2 sets of pads. Do you know the history of the car?

Don't take too seriously the barking about reusing rotors that are in spec. A lot of folks derive pleasure from buying new parts and throwing perfectly serviceable parts away. The only real utility in it is that it makes them feel good, it does little to nothing for performance unless you're operating on the ragged edge.

If you do decide to replace the rotors, go with a reputable manufacturer and don't skimp on replacement parts quality. The parts market these days is hard to understand, sometimes I get more for less and often times it's the other way around.

Well, at the rate of wear thus far, the next (3rd) set of pads would wear the rotors half the amount of the total wear or 28-26.6 = 1.4, then 1.4/2= ~0.7mm. Taking 26.6-0.7 = 25.9mm and the rotors will just be shy of being in spec at the end of the next set of pads.

Of course, rotor wear is a lot like the stock market in that previous performance is not necessarily a good indicator of future performance (but its all we have to go on).

and so what's going to happen if your rotors are 0.10- 0.20" too thin when your new pads are worn out? NOTHING! They won't be able to absorb extreme heat (only found on the track) as well as new rotors would but only a driver who's driven MANY track miles could tell the difference. There are mechanics out there who insist that whenever they install new pads they MUST install new rotors as well!- forget machining they'll tell you, and why? Money.

Thx everyone for your input especially the mathmatic algebra lesson,(im weak in that area) but based on that info i feel pretty safe on making that 3rd set off pads with original rotors go the distance,and as mentioned i do not track and never will,i do occasionally drive hard but don,t do brake power slides ect.For those interested at now almost 93000 kilometers (55000 miles) i am still on the original drive belt which looks like new (have a new spare ready to go if needed) original water pump with no play in the bearing,its tight ,smooth and quiet,just changed my plugs,because, and probably dident need to as they looked perfect,no metal in the oil filter either (IMSB OK) , have to say this car has been pretty reliable so far in the 30000 kilometers i have owned it! Thx again

Speaking of brakes, has anyone used the brake kit from pelican parts? It doesn't use genuine porsche rotors or pads, but does cost a few hundred dollars less

Use the rotors until they fall out of spec. The won't just quit working. Don't let them go to far out, but your car won't know if they exceed wear limits by a little. And you do not need to replace pads and rotors at the same time. A Porsche is no different than any other car in that respect.

FWIW, new rotors are like $125 for a set (either front or back). You don't need oem. It's easy to replace them yourself without any prior experience. So, if you feel a little on the cautious side, there's not a huge financial burden.

-td

While this thread is on the topic of brakes.

Are factory Porsche rotors considered the best or is there a premium aftermarket brand that is better? I hate when rotors show a rusty finish around the hub area.

How about pads? I will not be tracking my car but I like quite and low dust as priorities and wear longevity second.

I got some Balo rotors with painted hats and they were quite inexpensive and worked fine. No rust due to the hi temp paint on the hats. There are tons of different rotors including cross-drilled, mooned, slotted, cryo-treated, and a rainbow of prices but I think good old plain Zimmerman offer a good performance and value. YMMV

http://www.pelicanparts.com/catalog/shopcart/986M/POR_986M_BRKpad_pg3.htm

A ceramic-based brake pad will reduce brake dust substantially and should be equally as quiet as a standard metallic pad.

Real World Pricing
 

At my last tech inspection at an indy shop, prior to a track day, I was informed that I needed front rotors and pads (Est $800, installed) on my '01 Boxster S with 30K miles. I ordered $515 in parts from the very helpful and knowledgable guys at Pelican: Front pads $118, Vibration dampers $76, Retainer Spring Kit $39, Rotor Screws $4, Front Rotors (Zimmerman) $259 and Wear Sensors $19. I bought a "deep-throat" Fowler digital Metric Micrometer from Amazon for $61 to check rotor thickness and found that my rotors were well-within spec at 27mm (I think they get replaced at 22mm?). I set the rotors, etc, aside for a later date and just changed the pads and dampers, using $194 in parts. In retrospect, I could have re-used the old dampers, if I had purchased the right glue, but Napa isn't open at 6:30 AM, so I used the new ones and saved the old. This is an easy job for someone with very modest mechanical skill, but read Wayne Dempsey's write-up, buy a can of brake cleaner, and I find using 2 sticks, not one, is best for retracting the pistons. Pay attention to the level in the brake fluid reservoir when doing so.http://986forum.com/forums/uploads01...1372160282.jpg

VROD, AKEBONO pads have been recommended to me as a low-dust pad, however I haven't yet driven on them.

Topless, thstone, iaincamp & woodsman,

Thank you for all the good info. Tell me is there really any advantage to cross drilled rotors? It seems that maybe they could cool down faster. Does it affect the wear rate or feel when braking?

I have driven my Boxster on solid, cross drilled, and slotted rotors. On the street, I don't notice any difference in braking performance or feel in regards to rotor type. They all work fine, cool fine, and have pretty much the same feel to me.

On the track, drilled rotors cool better and therefore have better feel when really hot, but they also crack and need replacement earlier than solid or slotted. Solid and slotted felt the same to me on the track.

The pad will make much more difference than the rotor because each pad will have somewhat different characteristics of initial bite, stopping power, and heat resiliency.

I know this is late, but that is the stupidest thing ive read on this forum. Please do not give out ANY advice if you dont know what youre talking about. I dont know of any reputable shops that will slap new pads on unresurfaced rotors. You either replace the rotor, or you resurface it if it has enough material.

Not debating min. thickness, but here's nothing wrong with new pads on an unresurfaced rotor, as long as it's worn evenly, and isn't grooved. I've done it for 20 years on multiple vehicles, including a race car. After normal bedding in, they're as good as new. I've never found someone who would skim cut a rotor, they always take too much material.

I'm a machinist who's raced cars. Learn how to disagree without condemnation. This is a FORUM.

+1

Fear of reusing a serviceable rotor without resurfacing is pretty unfounded. It happens 50 times a day at racetracks around the world without incident. It won't have that "perfectly smooth, all new components feel" but it stops the car just fine.

As a shop owner, I personally took offense to your claim of "dishonesty" . I am straight forward with my clients, and I never use scare tactics to get people to do their maintenance in my facility.

In my experience, whenever I put a used rotor on the lathe, its usually worn unevenly or warped. This causes vibration and causes the pads to become noisy. The groves in the rotor overheat the pad ( since maybe 40% or 50% of the pad is making contact with the rotor until it breaks in ).

Can you get by if you slap new pads on an old rotor? Probably. Will you get cancer watching your food rotate in your microwave from the radiation coming out of it? Maybe, maybe not. Should you accuse a shop of being money hungry because they want their client to do the job correctly? Absolutely not.

I think clients would appreciate the OPPORTUNITY to gamble on their old rotors (turned or not) before they fork out for new ones. I know radial run-out can be a persistent problem but so can over-cautiousness or a lack of sufficient funds.

I agree with you. Went in to my indy, they said I needed new brakes (46k on odo) and I was enthusiastic about changing them out, but then the shop (diehard porsche fans, mind you) says I need new rotors, etc., and then throw that price out there.

What happened? I walked - can't afford that for just a brake job at this time, or anything else on their list that I got done for 25%-35% less at another porsche mechanic who is much more laid back about this stuff. Regardless, I have a brake pad light on and compromised safety with a car that is off the road during prime top-down weather.

Which is the better scenario for that customer on the road a few months later? I presume the "can't afford to drive a porsche" argument will be used against this statement. Maybe they are right in their recommendation--I'm not going to say they are flat-out wrong--they aren't. However, their "go oem or go home" attitude is well noted in the local community, and a turn-off for lots of customers.

I always replaced pads without even resurface the rotors. And usually it was ok. Each rotor took like 3 to 4 pads before wearing out of factory spec (on the Alfa Romeo that I had). I never used race performance pads (unless on motorbikes), just regular road use Ferodo or Brembo ones. The Brembos usually were better, but they ran out sooner too. On my motorcycle, I had a problem with the 2nd pair of pads, they started to vibrate a bit under slow breaking.

I am in total agreement with re-using safe(within spec, no cracks, etc.) rotors with new pads. Even unturned, in-spec rotors should do no more than wear the pads a bit faster.
But - We live in a liability paranoid world so if I were a shop, new pads, new rotors would be the standard job.
I don't even think a customer signing a release (Old rotors, in spec, legal jargon, Blah, Blah, Blah) would release a shop from liability if there were an accident that could be some how traced back to stopping the car

So if your car is pure shop repaired, pads & rotors would be expected
DIY - its your call and your responsibility to keep it safe

Well, driving around on worn out pads and out-of-spec rotors is probably not the best plan. Maybe time to learn how to do your own brakes. :)

New or turned rotors is just standard procedure and good business for a Porsche shop. It makes certain that the cars brakes are at their best and feel smooth, fresh, and new which eliminates callbacks from: "You guys said you did my brakes but I still hear a grinding noise. I'm not leaving until this car is right and I'm not paying for a job half done."

We Porsche drivers can sometimes be a PITA ;)

As a DIYer, I never resurface a rotor measured within spec that I deem serviceable. If it is heavily grooved, I go new. Rotors are cheap and expendable with front OEM Zimmermans at about $100. Hospital stays are expensive so choose wisely.

Would love the time to do this. That's partially why the car is sitting. Maybe I will get a chance to tackle it. The wear indicator flashed once while it was 100+ degrees out after some hard braking and hasn't been driven much since. No light, and no abnormal sound or feel.

Regardless, y'all make a good point about liability with mechanics. It makes sense, and I suppose complaining about it doesn't change that fact, so...DIY for me or wait 'til I can afford the full treatment. :)

Thats exactly what Im talking about! Noise and vibration are two big reasons the rotor needs to be smooth on a customers car, in fact, if a client insists I dont resurface his rotors or refuses to replace his rotors, I make sure to make him understand he has no warranty if his pads make noise.

Kk2000s, if you cant afford to do brakes on a boxster, you cant afford to drive. There is really no excuse not to be able to afford maintenance items like brakes when you have ebay and amazon at your disposal. You can do one of two things.

A. Buy the parts online and bring it to ANY reputable shop
B. Buy the parts onine, and do it yourself.

New parts worship
 

'The full service' probably includes new parts that many DIY'ers re-use: brake pad wear sensors, anti-vibration inserts and rotors. This is where knowledge and shopping around can get you what you NEED despite tight funds. In Canada, litigation is FAR less common and so the hysteria to ward it off is less great. The world is changing and soon shops won't even HAVE a lathe, designed and built, specifically for resurfacing rotors, as they've had for decades. Perfectionism costs and is partially responsible for the throw-away world were now stuck in. I say; IF IT AIN'T BROKE, WHY FIX IT?! underneath PERFECTIONISM IS THE FEAR OF FALLIBILITY--- lets keep it in perspective and our finances will follow!

Well said! Replacing rotors instead of machining saves alot of time, allowing more brake jobs in less time, by less skilled "technicians" How many shops discount the labor when they don't have to remachine the rotors? Bigsmoothlee?

I certainly discount the labor! It wouldnt be fair otherwise! Being honest, fair, having an excellent reputation will keep your shop packed with cars.

As for time? Yes, it takes less time to change rotors, But more brake jobs in a day? I get maybe 2-3 brake jobs a week. The rest is usually more complicated stuff

Well good for you, I agree with that theory. Kinda rare here in SoCA. With all the traffic brakes are big business here, I've seen 1 mechanic do 5 cars in 8 hrs. I don't know of any dealerships that still machine rotors. :(