360CS Brake Pad Wear Warning

I just replaced my front pads... 5200 miles of fairly aggressive driving... but a lot of highway miles as well.

The light would come on when I would press the brake pedal. The fluid was a little low (not below the low line, just not at max); we filled it up to max; then the light would blink periodically even when I didn't press. So, I ordered new front pads.

I was a bit worried that I might be replacing them early... as expensive as they are, I'd hate to do that. And, like you, figure Ferrari's sensor would be conservative (understandably). I'll post pictures a little later... but you can clearly see the mounting "posts" from the backing material showing through the pad surface on the pads of my left front... so the sensor seems to be about right.

If you look at the edge of the pads, you can see the lip of the backing material that extends out further than the pad. If you look at the space from that lip to the surface of the pad, probably 20-25% of that width is as far down as you can wear down the pads. When I take pics later I'll also measure to make that more accurate.

Incidentally, my rear pads are only about 2/3 worn in the same time.

Given that, your pads are probably fine. Even if you were thinking you could wear to the backing plate, a 75% estimate leaves you with plenty of pad. There are two other things that could trigger that light:

1) Low brake fluid.

2) Sensor problem... wire came lose maybe... a short somewhere.

Doesn't it!! I just hope those rotors last a lot longer than the "two pad changes to one rotor change" rule-of-thumb ratio! 10K will be horribly disappointing... in fact, that might-be-change-to-steel disappointing! However, based on my last two rotor wear numbers from the SD2, it would seem they are wearing at a rate that would give me 20-30K miles... which would be acceptable. The hard part is that I didn't look at the wear number when the car was delivered... I don't think it starts at 100% based on the rate of wear I have seen.

 

i thought i read in the manual that ferrari says to replace the rotors along with the second set of pads? i could be wrong. going from memory i'll look it up in the manual later this morning. rotors are expensive so i hope we don't have to replace them automatically after two pads. btw, i've seen prices all over the map for rotors, pads. do you have a pretty good idea of the cost?

 

Thanks for the info, Brian... I just hit 1000 miles on my CS and was wondering a lot about all of this. Here's hoping we don't have to replace rotors at 10,000

How much were the pads, btw?

 

Hey Brain, I was wondering about the material left on the pad. According to the manual it recommends "the minimum pad thickness allowed for the pads is about 0.12 of an inch (3mm) (thickness of the friction material only)."

Are your pads anywhere near that?

If they are and you really needed to replace them at 5200 miles, I just became concerned.

What was the cost of the pads?

If what 720 says about the 2 pad sets == rotor replacement, are you at all concerned about a potential $20k brake job @ 11,000 miles or only 1 year of use? I am.

 

Isn't warranty coverying any of this?

--Dan

 

My brake sensor light used to flicker in 270 degree onramp turns into freeway. I had plenty of pad but somehow the sensor inside the brake master cylender would sense low fluid and flicker under heavy g groing through the turn. Bled brakes topped it off and never had it come on again.

 

Car warranties do NOT cover wear-out items like brake pads.

Now, if they had worn out in 500 miles rather than 5000, I might have tried to make a claim... but at 5000 miles, although disappointing, I wouldn't expect much more than a chuckle from FNA.

 

Hey Brian - you own an M3 don't you? Maybe I'm confusing you with someone else, but anyway, all recent BMWs cover even wear items (except tires) on their new car warranties, and I have in fact had the brakes replaced for nothing, and clutches are also covered I understand. I'm sure there are other makes that do this also, in addition to covering scheduled maintenance. Ferrari lags a bit in this department, but I guess you can't have everything.

Gary

 

i searched through my owners manual twice andi did not see anything about replacing the disk rotors after two sets of brake pads. i could have sworn that i saw this in the owners manual. i also did not see any details describing how to "bed" the brakes after replacing the pads. again, i could have sworn that i saw very detailed instructions on this in the manual. i have two stradales so i suppose it's possible that the owners manuals were updated/revised. i reviewed the manual in my older stradale tonight and found nothing. my newer stradale is in the shop (something is rattling in the exhaust so FOC is fixing it...should have it back in the next couple of days). when i get it back i'll pour over the manual to see if i find any more info on brake rotor replacement and bedding brake pad procedures.

 

Yes, I have an M3... and yes, I enjoyed "scheduled maintenance" while I had it... and I think that (rather than the warranty) is what was replacing your wear items like pads. But I certainly haven't memorized the wording of the BMW warranty!

 

I am reaching 7000miles now – around 1400miles track - the remainder backcountry roads

My pad level remaining is 10[mm], which is still 90% - 3 [mm] friction material is the minimum

Brian it would be really interesting to get the thickness of your old pads – do you do a lot of threshold barking triggering ABS (I assume not …)?

I was getting very comfortable with the system especially since my disks look perfect so far – no cracks emanating from holes – no patches of broken away material – disk surfaces smooth

 

I don't think its in the users manuals. I think the former was from a note sent to the dealerships. The latter is from the service manuals, I believe. I asked for the bed-in instructions, of course... and they pulled it off their system and printed it for me. Guessing by the file name, it is in chapter 3.21 of whatever manual it is in.

 

I did post the instructions form the Workshop Manual sometime ago – I don’t think it is in the owner’s manual – I wonder if they bedded Brian’s new pads at 200kmh ....

Don’t get me started with the exhaust – the U-bracket that holds the end-pipes together broke with my “old” CS – very nasty vibration at specific RPM – dealer welded it on and it worked

my new CS has a changed design with the U-backed screwed on - it broke again and even worse since it will be very hard to weld it on again – the new design looks like the intern designed it; it can not work

The heat shields on the new CS (search for pictures I posted before) attached to the muffler left/right vibrate like crazy at 4000RPM – it is very impressive to see; it look like liquid in that state – mine are full of cracks now

Luckily I have had a second CS exhaust (of the old design), which I bought some time ago to get it ceramic coated – never got to it – so I replaced it – dealer tries to figure out what to do with the new exhaust

A broken exhaust makes a nasty sound for sure ….

 

My new pads (one weekend old) are 11mm, measured from the wider backing material to the pad surface. My old ones:

Left outside: 3.8mm min to 4.8mm max
Left inside: 4.3mm min to 5.3mm max
Right outside: 5.8mm min to 6.9mm max
Right inside: 6.8mm min to 7.6mm max

Hmmm... where did you get the info that 3mm is minimum? My dealer didn't have that info to offer. But then again, they're going to be conservative and "obey" the sensor.

But if the range is 3mm-11mm, so 8mm=100%, then I still had 10% left on even the worst pad. On the better pads I still had at least 47%!! Glad I saved those. With an $1800 price tag, those right ones will be going back on!!

HOWEVER, look at the attached pic of that worst pad... the brass-colored posts are clearly visible right at the surface... I don't think I want those actually contacting the rotors!! I think 3mm might be dangerously low.

For those curious about the wear pattern, I trail brake into many more right handers than I do left handers... putting more strain on the left front.

I do a fair amount of threshold braking... but I generally stay out of ABS... but when you're there, any non-trivial changes in surface can result in a pulse or two before I back out a bit.

My disks look great also. Definitely none of the cracks typical with steel rotors. The surface looks just like it did when it arrived. HOWEVER, I wouldn't call it smooth... it has deliberate-looking texture to it.

My pads, on the other hand, have lots of cracks in them. And the more worn down the pad, the more cracking. And there does seem to be some material missing even. Unfortunately, I didn't get a look at the new pads before they went on.

 

That is staggering... how can our brake wear be so dramatically different? (I assume you drive the car hard on the track... what run groups are you in... novice, intermediate, advanced, instructor?)

What temperatures (air) were your track days?

I assume you are using the stock Pirelli tires. Are you?
When did you run through your first set of tires? How much tread did you have left when you replaced them?

 

Great thanks for the info Brian

The 3[mmm] comes form the owner’s manual – see attachment

I am surprised about the differences as you are

most of my track driving is done at the Pacific Raceways - my fastest laps are around 1:40’s, which is right up there with the purposefully build race cars – see SCCA results http://www.nwr-scca.org/race/Results/2004/2004R_Results_5-30-04.htm - this is surprising to me since I am not driving 10/10, which you would understand if you could see the runoff space in most of the turns (track is 2.2 miles long) – you can find more data in the Northwest Region of FChat

Ray who has a CS too may be able to add some insight he has more experience with race tracks in the NW than I have

I am running my third set of tires, each set usually lasts three track days – I run the PZero Corsa’s – the last set has been shaved and I replaced them with no thread left (front and rear) – I like to slide the rear

Pacific Raceways is a technical track with top speed around 140mph – normal temperature around here is 80F – two track days have been part-time rain (fun with the CS)

I avoid ABS like hell – I did find a technical analysis of carbon brakes used for airplanes – the conclusion was that the short and pulsed braking (during taxiing) is the worst case scenario – max temperature I have seen with my brake disks in the pits is 285F since I stick to cool down laps religiously

I like to setup my car early and try to carry momentum through the turn optimizing for exit speed

Not sure what Ray’s brake wear is – we have been at the track several times together – Ray?

 

The cracks don’t make me feel comfy

what did the F folks say? – they are usually very interested in the brakes; my dealer goes out of his way to take a look at the brakes after each track day – they also said that they communicate everything about the CS to the factory

The Workshop Manual has an example of a bad pad; unfortunately the picture is so bad that one can not see if there are cracks in the friction surface – however they are obviously concerned about excessive heat and discoloration of the edges

 

Discoloration of the edges? What kind of discoloration?
I do have a rusty orange on some edges... I'm used to seeing rust on brakes... but now that you mention it, not sure a carbon ceramic brake should have any rust.

 

Based on all that, particularly tire wear, sounds like you are driving at least as hard/fast as I am... probably harder. Though exactly how hard on the brakes depends a lot on the track...

You brake from 140 down to what? What are the biggest braking turns? How many total turns? How many require significant braking?

That's a clear difference. It gets a bit hotter than 80F here.

I guess from now on, I'll too be avoiding it like the plague... at least until I see if that makes a difference.

Likewise on the cooling the car down. I'll start checking disk temps regularly.

That may be another difference... I like to brake late and trail brake into the corners. Obviously I still want to achieve optimal exit speed, of course. But I may compromise mid-corner speed a bit by braking later.

 

My dealer mechanics didn't comment on it... so, I don't know that the factory even knows... unless they are reading this thread. I don't suppose they'll comment here? Or maybe a Brembo engineer?

 

One more thing, Thomas... you MUST get your car hooked up to the SD2 and have them pull rotor wear! It will be VERY interesting to see your numbers vs. mine. Based on pad wear, we'd have to assume my rotors are more worn. But based on total miles and track miles and having gone through 3 sets of tires, I'd bet the "rotor wear calculation" would show your rotors as more used up.

 

Brian: I was told locally (FoSF) that first brake change is free. Dunno if that includes a whole set of rotors or just pads or what. I think that we can campaign for something.

--Dan awaiting PPI on his titanium stradale

 

Really!? Got a name I can point FoD to talk to?

 

Be careful, factory dealer is different than franchise dealer. But it never hurt to ask.

Brian, I just think as ridicules as it is to change brake pads after 5K miles for a street car, it does make sense for a CS as you seem to be on the track every chance you get. Do you flush the brake fluid after each track day and change the motor oil as well? The pads on the other hand are not that much more expensive than regular 360 pads at $1200+. Did you look for those Brembo pads from Pagid or Fredo,...