First time doing brakes on my 2001 996 C4. My "Brake Wear" light came on yesterday.

Any important mechanical advice, tips/tricks?

Advice on best parts prices you've found?

Can you turn Porsche rotors, or must replace every time?

Parts Dealers - please don't hawk and respond to this. I'm looking for advice from my fellow car owners. No offense.

 

Let me chime in here: First, the parts dealers on this forum are a wealth of information and are a valuable resource and many offer technical information on their websites, so don't discard them.
As for the brakes, you cannot turn the rotors, in some cases you can get 2 sets of pads to the rotors, unless you use ceramic pads which are less dusty but eat the rotors. Use a good street pad or OEM and make sure they are made for the sensors. Other than that I believe it's pretty straight forward.

 

You might want to buy new brake sensors since they are easy to break especially if you've not done it before. Also it not reusing the anti squeal pads you need four per wheel if so inclined.

 

Thanks, guys. First of all, I had seen suppliers respond to other posts and figured that's why their on here in the first place - to stir business. I'm not blaming them, but had in fact discounted that they might also be able to help us. Thank you.

Thanks for advice about sensors, pads and rotors. I'll get some bids.

 

I know of no reason why the Porsche rotors can't be turned but it is rare they are turned. In fact I can't recall anyone in fact doing this.

For my Boxster and I don't see how this would be any different for the 996 I have replaced just the pads when my check of the rotors found them still serviceable.

A brake bedding in procedure after the new pads are installed gets the braking action up to snuff in practically no time and brake performance and service life is just fine.

When doing the brakes I always order the brake hardware kit. I forget now the names of the parts in the kit but every piece of hardware that one must remove to do the brakes -- except the wheel bolts, of course, is included except maybe the caliper bolts.

I can't recall if these come with the kit or not but if I replace the rotors and of course have to remove the caliper I replace the caliper bolts too. These are not stretch bolts but they are exposed to the elements and I have found the ends to sometimes show signs of corrosion and rather than wire brush this away and try to find some "sealer" (aka grease) that will hold up to the heat and elements (ain't any) I just replace the bolts.

I do one wheel at a time so I have the other wheel and its untouched hardware as a reference.

After I remove the wheel and before I start taking the brake hardware apart I use some brake cleaner -- the stuff that comes in an aerosol can -- to clean the hardware, the caliper and the the brake sensor wear and its connection.

Put down some layers of newspaper to catch the fluid as it drips off and carries with it the considerable brake dust.

This reduces -- but does not eliminate -- the dust you encounter when you start removing hardware.

After you remove the hardware then do another cleaning prior to installing the new hardware.

Be careful that when you push apart the pistons the fluid level in the brake fluid reservoir does not over flow. You can remove some old fluid -- use an old turkey baster (you'll have to carefully remove the screen that covers the opening of the reservoir) -- if you want but remember the brake fluid level can be low after you are done. 'course, after you are done a brake fluid flush and bleed is a very good thing to do. Don't forget the clutch slave bleed too if the car is equipped with a manual transmission.

Sometimes I just order new wear sensors, other times if the wear sensors are intact I reuse them, although I keep in mind one may light the warning light if it proves to be bad or goes bad. I'm prepared to go back and replace it (and its mate on the other side) should this occur so this slim risk doesn't bother me.

Believe it or not I have even reused sensors that were a bit worn from contact with the rotors but I do not recall if I did anything special. Really in the overall scheme of things the new sensors are inconsequential to the price of the brake job so my advice is to just replace them with new ones. (Do as I say not as I do...)

Pay attention to your work and avoid distractions and interruptions to your work. The brakes are a vital safety system of the car and must be done right. If you mess up and even if you avoid any accident improperly installed or left loose brake hardware can wreck havoc on other expensive components.

Oh, except for one time I have bought my rotors/pads at a local dealer. Even from the dealer parts department I can tell you the pad brands were different -- I do not recall the various brand names now. I can also tell you brake dust production and brake life were different between pad (and possibly rotor) brands but I can't recall the combinations that delivered the least amount of dust and the longest life. At the time I was installing the new hardware it never occurred to me to note the brands used.

In all cases though brake action was just fine and I never felt any combination of pad/rotor brand delivered sub-standard (or even less) braking action than any other combination. I never bothered with "low dust" pads or fancy "track" pads I just used/installed whatever the parts counter manager shoved over the counter at me when I picked up the hardware.

 

Slotted drilled rotors can be turned. this has been discussed many times.

Do you guys have recent articles that state they cannot be turned?

 

If you turn CD rotors they don't dissipate heat nearly as well, and in turn, the structural integrity of the discs are compromised. Cross drilled rotors are harder to turn and in doing so often results in some issue in consistency of thickness. The cutting bit can be miss guided when hitting the holes. It's possible but not as easy. If you do decide to try, have someone who's done drilled rotors before. Often, it's simply not worth the effort.
Porsche states if there is any "lip" on the edge the rotors should be replaced.

 

As an ex-journeyman machinist there is no reason why a good tech with a good brake lathe couldn't get consistent thickness turning cross drilled or slotted rotors.

The rarity of this operation probably arises from brake shops and their reluctance to do this operation.

'course, there is the requirements of a good tech and a good brake lathe. While I have encountered both in some places often one or both are lacking in other places.

However, even with a good tech/brake lathe operator and a good brake lathe it can take time, at least two passes. The first to clean up the surfaces of the rotor, the 2nd pass as a finishing pass.

There is also the question of how much deviation is there between different rotors? I have no idea of what's ok and what's not ok.

But to ensure both rotors end up at the same thickness and still have the legal amount of metal, the brake lathe operator had better be pretty darn good at guessing which rotor is the worst one and getting it cleaned up then bringing the other rotor to its thickness.

There can be an issue with CD rotors if the holes are *not* chamfered properly, sufficiently deep enough.

Often the CD holes are not drilled but cast and as such have some nasty scale maybe even casting sand (embedded in the scale) still in the holes. If the turning operation gets "below" the chamfering the cutting tool can be chipped from this scale. A work around is to re-chamfer the holes before the resurfacing operation.

However, there are a lot of holes and one doesn't want to take the chamfer too deep nor not deep enough so some kind of a drill press with a fixture to hold the rotor and limit the depth of the chamfer to ensure it is 1) deep enough; 2) not too deep; and 3) for looks' sake all are the same depth; adds even more time to the job.

Also, as the scale in the holes is hard on the rotor surfacing tool it is likewise hard on the chamfering tool.

Now if the brake lathe uses a grinding wheel to resurface the rotors this pretty much eliminates the issue with holes and chamfers. But that machine is going be pretty complex and more expensive and thus the operation will cost more.

A lot of extra time to do this right, and this extra time probably turns off most shops from doing the rotors. If one was required to pay for this labor new rotors might be the less expensive option.

Easier for the shop to just say it doesn't turn Porsche (really any brand of) CD/slotted rotors and be done with the whole mess.

As for the lip thing, that's going to ensure in almost all cases the rotors will be replaced. Rotors develop a lip quite soon after being put into service so unless the rotor is nearly new and one is just replacing the pads due to possibly a bad (defective) pad the rotor will have the lip and thus should be replaced, according to Porsche.

 

Did you happen to use the Blanchard process?

 

Just wanted to share my two cents here -

When I first got my C4S, my brakes squealed like a pig in the last 10 feet of coming to a stop at light/moderate pressures.

I inspected the pads and they had about 50-60% life still left in them on both front and rear. Either way, I decided to replace them - ordered some aftermarket textars (as I've read they're the 'OEM supplier' to porsche brakes anyway).

When I went in to install them, I notice the previous squealing pads were the exact same textars. The previous owner had also removed the brakepad dampers (the mushrooms / spiders) completely, perhaps he was a track guy and wanted to be able to change the pads easily.

Either way, I just swapped the pads, and they still squealed.

I went back and ordered genuine OEM porsche pads for all 4 wheels, and the brake pad dampers as well for all front and back calipers. One interesting thing to note - the "genuine porsche" pads looked just like the textars, except that they had two round weights at the top - on both the front and rear units.

Once I put in the new dampers and pads, the squealing went away completely. Totally silent braking, it was a huge relief.

I can't say for sure whether it was the genuine OEM pads with the weights, or the dampers that removed the squealing.

But.. don't skimp, go with genuine porsche if you can, and don't remove the dampers I've read some people have squeal free brakes without the dampers, using textars as well, but that wasn't the case for me, unfortunately!

 

Use videos on this page before working on your brakes and rotors.https://www.youtube.com/results?sear...n+996+portsche

 

If you're careful you can reuse the dampers.

 

Sold