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.