Rs4 2014 brake failure and crash. 45k in damage.

[B8RS4]

ss

[chet]

I know a few people with TT-RS's who have had ongoing brake issues, including a failure at the track. I really don't know what the deal is with all of these issues, but I'm glad you're okay. :(


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[bhvrdr]

Sounds like you boiled the fluid then if brakes are back. Sorry it happened. I'm surprised the pedal was getting soft though. Let us know if any malfunction is found.

Mike

[shonseb]

Sounds like you boiled the fluid then if brakes are back. Sorry it happened. I'm surprised the pedal was getting soft though. Let us know if any malfunction is found.

Mike

This is what I was thinking

[jran76]

Sounds like you boiled the fluid then if brakes are back. Sorry it happened. I'm surprised the pedal was getting soft though. Let us know if any malfunction is found.

Mike

This. While you'd typically see some fade or softening of the peddle first, it's not out of the question to see a sudden change like that on something like the stock fluid. What kind of brake fluid were you using?

There is a chance a brake line or something like that could have happened. It would likely take either boiling or losing the fluid to completely loose the brakes.

[b8audis4]

Yes, sounds like fluid boiled to me. If that is the case a race brake fluid would have helped. Glad you are ok.

[will13k7]

that sucks man, but without the right pads and fluid, what comes with the car isn't suitable for track duty.

[RecklessactN]

What was your brake setup for the track? Pads/Fluid/Stock Rotors?

[Thurston]

What was your brake setup for the track? Pads/Fluid/Stock Rotors?

but to his point, shouldn't the stock set up be able to handle tracking? Although five laps in I bet those brakes were hot as hell. It reminds of when the first generation porsche cayman owners realized they actually could not track there car w/ out it blowing up due to g-force oil issues.

[Quattroborn]

If you were on stock fluid and pads. . . I hate to say it but it's 100% your fault.

[seanj130]

How long was each lap? How many corners on the track?

Did you purchase track insurance for the day?

Audi pride themselves on how hard you can drive the RS cars. they say they are built for it and can run and run and run. That is one of the main selling points of the car. for $140,000 you do not expect the brakes to fail. They are some of the best money can buy.

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[jran76]

Stock brake fluid just isn't made for high temps like that. The trade off with a higher boiling point brake fluid is they will pickup more moisture over time, and need to be changed more often. For that reason, it's just not going to be used on a stock Audi (RS or not).. I hate that this happened, but you should never track an Audi on stock brake fluid.

[bhvrdr]

OP, I do agree with you that the stock brakes SHOULD be able to handle a track day but unfortunately I have yet to find an Audi that didnt have brakes as their weak point. Some cars are weak in power, in handling, in refinement, etc but with Audi it seems to be brakes. I was able to hammer the hell out of my IS350 brakes doing 50 minute sessions and I wore through the pads before I boiled the fluid. Thats not the case with an Audi ive take out for a lap day.

edit: as jran stated above at the very least you would want to be going out on a fresh synthetic high temp brake fluid and with at least 80% pad life.

Mike

[Thurston]

Audi truth in engineering *but you may want to outsource your brake fluid just in case of catastrophic failure when driving hard.* nah but seriously surely there are more than a dozen other RS owners who have tracked w/ a stock set up who can chime in or maybe they all agree you should have changed to high temp fluid idk. After the first 8 laps, i don't think I would call it a light work load kind of day but still. (a quick google search reveals a handful of audi r8 owners that have experienced boiling fluid at track days as well)

[JoshDub]

Sounds like you boiled your fluid.

Chalk it up as a learning experience. Bet you never skimp out on brake fluid again.

[jran76]

Audi truth in engineering *but you may want to outsource your brake fluid just in case of catastrophic failure when driving hard.* nah but seriously surely there are more than a dozen other RS owners who have tracked w/ a stock set up who can chime in or maybe they all agree you should have changed to high temp fluid idk. After the first 8 laps, i don't think I would call it a light work load kind of day.

I'm pretty sure the RS4/5 use the same fluid as the S4/S5. At least in the states, it's Audi's DOT 4 fluid (maybe NZ is different). It has a dry boiling point of 509F (265C), and wet boiling point of 338F (170C).

By contrast Motul RBF600 is 594F/421F (almost 100 degrees F higher). Motul RB660 is 617F/399F. Castrol SRF is 590F/519F.

[jdmnomore]

Stock brakes on pretty much any car are not going to be sufficient for multiple hard laps. At a minimum you have to address fluid and pads. Very sorry to hear about the damage to car and glad to hear youre ok OP

[Thurston]

I'm pretty sure the RS4/5 use the same fluid as the S4/S5. At least in the states, it's Audi's DOT 4 fluid (maybe NZ is different). It has a dry boiling point of 509F (265C), and wet boiling point of 338F (170C).

By contrast Motul RBF600 is 594F/421F (almost 100 degrees F higher). Motul RB660 is 617F/399F. Castrol SRF is 590F/519F.

I'd say that, that honestly sounds like a fairly high spec fluid Audi is using but I don't know much.

Wasn't there a white s4 that had brake failure (supposedly) or maybe they locked up during a tale of the dragon run? caught on fire in a ditch if i remember correctly.

[paul]

but to his point, shouldn't the stock set up be able to handle tracking? Although five laps in I bet those brakes were hot as hell. It reminds of when the first generation porsche cayman owners realized they actually could not track there car w/ out it blowing up due to g-force oil issues.

No. As much as they hype up our cars as performance sedans they are still street cars. The B8 is a heavy pig and will easily overwork stock brakes as a whole.

[boro92]

I'm very glad to read that you walked away unscathed, and you are healthy enough to post this and also be angry :) Which by the way, you should be angry.
But FWIW, this type of brake failure can happen on any brake setup--including big brake kits. This is what happens when street pads are used in the track. It forces the driver to be on the brakes longer than is ideal, and it puts a lot of heat in the system. Eventually, the brake fluid boils and you lose all brake pressure. This is why brake checking on high speed tracks is a common thing to do (just dab it with your left foot to make sure pressure is still there before your braking zone). In future, if you hit the brakes and it goes to the floor, you just need to pump it a few times to build pressure--the brake booster will do this for you. FWIW I have lapped many sessions with my brake to the floor and lived to tell the tale. You just need to know what to expect.

This is where the danger lies in high speed track driving. A driver must anticipate what can happen. And it's good that you walked away from this. Do not take offence to the following comment--I'm being fully objective here. But, rather than put your frustrations and disappointment on the car however, it should be taken as a learning experience. Driving high power cars is always a gamble, and knowing how to deal with these things is absolutely part of driver development.

As another aside, if a crash is going to happen and you still have some control of the car, you should try and aim the car head on. A side impact is where the car is least reinforced, and it is also where you have the least neck protection. I know a number of drivers who have lost their lives on the circuit from hitting the wall in this sideways manner. Head on is the way to go (sounds counter intuitive, but you have the most crumble zone there, the biggest airbag and with a street seat, you have no halo bucket seat support or HANS. The best way to preserve your life is a head on collision if you can make it happen).

My 2c. A driving instructor would say the same. FWIW.

EDIT: if you are very interested in learning and continuing down the path of driver development, knowing how to preserve and manage brakes is a skill that needs to be learned as well. Most drivers commonly believe that using the brake pedal softly, and braking earlier is how one preserves the brakes--however, the absolute opposite is true. Be on the brakes for as little time as possible. The less time you are on the brakes, the less heat is put into them and the more time they have to cool. Even if you get on the brakes 0.5 seconds later for every corner on the track...on a 10 corner track, you are touching the brakes for 5 less seconds than you normally would. Over a course of an entire session, it can even add up to an entire minute less of brake use. That's a lot of reduced heat. Changing fluid/pads is one thing. But how one uses the brakes is the primary factor in making them last.

EDIT 2: Don't get caught in the marketing mumbo jumbo of any car manufacturer. a BMW M car, a AMG, an RS, a GT500. Whatever. The fact of the matter is that they all come with street pads. There are race pads for a reason. No street pad will handle track abuse--especially not in a 400+hp car that weighs as much as this car does. The only cars you can take to the track in stock form without worrying about brakes is like............a miata, or frs or civic type r. Those things. Physics.

[Thurston]

No. As much as they hype up our cars as performance sedans they are still street cars. The B8 is a heavy pig and will easily overwork stock brakes as a whole.

yeah which is probably why the b8 is better fit to be a 1/4 mile queen rather than a country road / track king.

Good post Boro92 .

[agent47]

I'm very glad to read that you walked away unscathed, and you are healthy enough to post this and also be angry :) Which by the way, you should be angry.
But FWIW, this type of brake failure can happen on any brake setup--including big brake kits. This is what happens when street pads are used in the track. It forces the driver to be on the brakes longer than is ideal, and it puts a lot of heat in the system. Eventually, the brake fluid boils and you lose all brake pressure. This is why brake checking on high speed tracks is a common thing to do (just dab it with your left foot to make sure pressure is still there before your braking zone). In future, if you hit the brakes and it goes to the floor, you just need to pump it a few times to build pressure--the brake booster will do this for you. FWIW I have lapped many sessions with my brake to the floor and lived to tell the tale. You just need to know what to expect.

This is where the danger lies in high speed track driving. A driver must anticipate what can happen. And it's good that you walked away from this. Do not take offence to the following comment--I'm being fully objective here. But, rather than put your frustrations and disappointment on the car however, it should be taken as a learning experience. Driving high power cars is always a gamble, and knowing how to deal with these things is absolutely part of driver development.

As another aside, if a crash is going to happen and you still have some control of the car, you should try and aim the car head on. A side impact is where the car is least reinforced, and it is also where you have the least neck protection. I know a number of drivers who have lost their lives on the circuit from hitting the wall in this sideways manner. Head on is the way to go (sounds counter intuitive, but you have the most crumble zone there, the biggest airbag and with a street seat, you have no halo bucket seat support or HANS. The best way to preserve your life is a head on collision if you can make it happen).

My 2c. A driving instructor would say the same. FWIW.

EDIT: if you are very interested in learning and continuing down the path of driver development, knowing how to preserve and manage brakes is a skill that needs to be learned as well. Most drivers commonly believe that using the brake pedal softly, and braking earlier is how one preserves the brakes--however, the absolute opposite is true. Be on the brakes for as little time as possible. The less time you are on the brakes, the less heat is put into them and the more time they have to cool. Even if you get on the brakes 0.5 seconds later for every corner on the track...on a 10 corner track, you are touching the brakes for 5 less seconds than you normally would. Over a course of an entire session, it can even add up to an entire minute less of brake use. That's a lot of reduced heat. Changing fluid/pads is one thing. But how one uses the brakes is the primary factor in making them last.

EDIT 2: Don't get caught in the marketing mumbo jumbo of any car manufacturer. a BMW M car, a AMG, an RS, a GT500. Whatever. The fact of the matter is that they all come with street pads. There are race pads for a reason. No street pad will handle track abuse--especially not in a 400+hp car that weighs as much as this car does. The only cars you can take to the track in stock form without worrying about brakes is like............a miata, or frs or civic type r. Those things. Physics.

Very informative post and exactly what I learnt during the track day at COTA with Cadillac. The instructors would repeatedly tell everybody- keep your foot off the brake pedal unless you have to absolutely slow down. Try to handle the car with your gas pedal and steering wheel. OP glad you walked out of it. Cars can be fixed/replaced. People can't. Hope things get better for you!

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[Luna's S4]

My first two track weekends were on the stock braking system, with instructors. No problems. The third was on a AP Racing 380 kit with Motul 5.1. No on board instructors and no problems. The fourth weekend was a different story as I really pushed deep into the corners, thinking I was improving my time. No instructor and I have no idea if I was improving times but was catching the group that went out ahead of me. It was intoxicating. Second session, 3rd lap and brakes were gone on turn 7 or so. I limped around and pulled into the hot pit. Pretty sure I boiled the fluid.

This may not help you but there does appear to be some similarities. Cheers!

[F16HTON]

Hey Luna, were you in a s4 or Rs4? also it sounds similar. just trying to see if it has happened to anyone else in their Rs4. by the sounds of it there arent many Rs4's in the USA? Please correct me if I am wring however there was some stats brought out on Audi owners and New Zealand has the highest Rs car ownership per capita than any other place around the world.

Audi does not sell the RS4 in the USA

[RecklessactN]

Hey boro92. Yes I fully understand what you are saying. There was no warning however. I have tracked many other Rs cars and the Rs4 with professional drivers around the same track and have pushed the same stock cars with stock brake set up and there has been no failure. Im not angry as Im able to walk away from the crash. The car can be fixed and or replaced. I am more just seeking information on why this happened. Thoughts of mine were that there was boiling of the brake fluid. HOWEVER, people from Audi who take the track days advise us to take our cars out there with no modifications and just GO FOR IT. I do not suspect that it was human error in this instance.
From a personal side, Im quite used to driving high horsepower, high performance race car and street cars. Before taking the Audi out I was driving my 2003 Mk4 R32+t with 650hp.
Only noted that for your information just so we know that I'm not an noivice driver.

I suspect as well a fluid or pad overheat. Do you know what the ambient temperature and humidity was?

[LINDW4LL]

Guys, OP has the carbon ceramics too. Definitely a bit surprising to hear. It would be one thing if it were the steel brakes.

Stock brakes on pretty much any car are not going to be sufficient for multiple hard laps. At a minimum you have to address fluid and pads. Very sorry to hear about the damage to car and glad to hear youre ok OP

No. As much as they hype up our cars as performance sedans they are still street cars. The B8 is a heavy pig and will easily overwork stock brakes as a whole.

[Luna's S4]

S4. This could be model specific. However, I think it's more of an operator error. Sorry.

[Thurston]

Guys, OP has the carbon ceramics too. Definitely a bit surprising to hear. It would be one thing if it were the steel brakes.

interesting. What's the benefit of the carbon ceramics again?

[boro92]

OP if it wasn't the fluid, it's possible you had a line burst at the fitting. This also happens on track days :(
Pretty crappy either way. Again, glad you're ok and figuring out what wen't wrong. My driver tips were not suggestive of you being a novice, but rather, to keep the discussion going and also provide a point of view that is outside of "i need an upgrade" (which sometimes tends to be the common thought. But as we all know, driver mod #1).

[LINDW4LL]

interesting. What's the benefit of the carbon ceramics again?

The relevant points are that they have much better thermal capacity. It's quite hard to fade carbon ceramics. I believe the fluid stays cooler, too, due to the better heat dissipation of the carbon ceramics.

[jdmnomore]

Didnt realize ceramics.. that sucks. Defintiely gives you plenty more room before something like that should happen

[IceFour]

http://www.audizine.com/gallery/show...g-8414&cat=559

http://www.audizine.com/gallery/show...g-8434&cat=559

http://www.audizine.com/gallery/show...g-8393&cat=559

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Glad you came out of it ok.

[IceFour]

IceFour sorry you can see them here. http://www.audizine.com/gallery/

they are the white Rs4 ones

Ouch man. :( Must have been scary

[B8RS4]

yeah. nothing like flying into the corner and pressing brakes and there is nothing there at all. then just looking at the wall.

[GeoJoe]

yeah. nothing like flying into the corner and pressing brakes and there is nothing there at all. then just looking at the wall.

Oh hell...

[shonseb]

On closer inspection, looks like the stock 'wavy' RS brakes, not the ceramics:

[IMG][/IMG]

However caliper does appear to be larger than the stock

[Oloung1]

yeah. nothing like flying into the corner and pressing brakes and there is nothing there at all. then just looking at the wall.

those pics are brutal! OP at least you connected with a compression barrier and not into a set of armcos, making it out alive.

so what is the difference between the cool down periods of a half day track session versus a manufacturer sponsored HPDE that lasts all day, for multiple days, in stock cars, in all weather conditions? ive been to a b8 a4, porsche 991 and cts-v gen2 hpde. the cts-v cars were driven the hardest and iirc had less than half hour cool down times per 3+ laps each at PBIR.

[amz]

Subb'd I want to know what happened. I'm also suspecting brake fluid boiled. When was the last time you changed your fluid?

[RecklessactN]

On closer inspection, looks like the stock 'wavy' RS brakes, not the ceramics:

[IMG][/IMG]

However caliper does appear to be larger than the stock

Those are the OEM R8/RS5/RS4 rotors (Steel). Does the RS4 have brake ducts to cool them down? There are no ducts in the S4 and it is a problem even with upgraded BBK/Pads/Fluid.

[boro92]

OP curious to know...when the pedal went to the floor, did you get a vhance to pump it and see if pressure recovered? That would isolate whether it was a brake line or fluid issue. Fwiw the wavey rotors dont have much thermal mass, so theres that too : (