http://www.mazdas247.com/forum/showt...3684925&page=3

This is something everyone should read and watch. A fellow MS3 owner had a harrowing experience due to brake failure. He walked away (luckily) from a 110mph side impact to a tire wall. I'll leave the rest to reading.

EVERYONE WHO DOES TRACK DAYS, bleed your brakes and check your pads after every run.

 

brakes are definitely no joke.

 

I'm not going to comment on what I really think.....

If you do track days you either need a good mechanic that you visit before and after every event.....or you sure better learn how to do minimally difficult maintenance like brakes, oil and fluid changes...etc

I've had HP+ pads like that last one day at the track and be almost down to the backing plates.....if you are driving hard...you need to check them every day. And you need to change the fluid and bleed them often as well.

And there are much better compounds if you intend to track a lot that stop better...and don't melt away

 

What I really think is that he lied and only replaced the outside pads with the new ones. I think that he either:

1. Didn't know how to replace the back pads

2. Thought he replaced the back pads

Now he's blaming poor ol ABS

 

https://www.rx8club.com/rx-8-racing-25/ms3-crash-130608/

 

1/3rd pad thickness is playing russian roulette. 5/8th is the least I will track with (and what's recommended by several HPDE venues).
I've never had any erratic HP Plus wear on my car. Perhaps if I'd step up to R compound, the HP Plus would be overwhelmed, but on a 220 treadwear street tire, the HP Plus have done just fine.
Fluid should be bled before every event.
Also, ABS should be reserved as a safety parachute in brake zones (in general).

 

Since the calipers are like the RX-8 ..... floating calipers...it is possible that he had sticking issues...causing one pad to rub constantly and wear down a lot faster.

I always shoot brake caliper and rotor temps on all 4 wheels when I stop

If there is rubbing issues...one will be much hotter than the others...

 

I'm the last person to comment on anything track related, but the 5 P's do come to mind...

 

It sounds like he had a brake system failure or extreme brake fade. To have a brake system failure the brake pads would have had to be completely gone and if that was the case, they would have been making noise for a while. I have changed 100's of sets of brake pads on all makes of vehicles and I have never seen all 4 brake pads wear uniformily or even 1 pad wear at the same rate. What I mean is that the edge of the pad would have worn out faster then the middle, so he should have heard some grinding for a while before there was no brakes. With low pads the fluid will heat up fast causing premature brake fade which was likely the cause. Another posibility is that a brake line leaked, a caliper started leaking or the master cylinder failed. Either of the 3 posibilities could not even be detected until the failire occured which was likely on the track, so an inspection 1 minute before hitting the track would not have found anything. Once a system starts leaking it is almost immediatly noticible, the pedel goes low or feels soft, so the best test for a brake leak is the feel of the pedel. if it feels wrong, check for a leak. keep in mind that the pedel will feel soft when the brakes are hot, so always check them cold.

There has been mention of bleeding the brakes before and after every track day. My recommendation is that you do not bleed your brakes unless there is a problem, flushing the fluid every 15-20K miles is a good idea but if you bleed your brakes too much, you are increasing you chances of getting air in the brakes (meaning you did it wrong) or even damaging the master cylinder if you use the brake pumping method, (not recommend on ABS vehicles use a vacuum or suction device). The reason you bleed brakes is to remove air from the system. A brake system is air tight and unless you have a leak, there is no way for air to enter the system, meaning there is no reason to bleed them.

So as mentioned above, the likely cause of his brake failure was brake fade caused from overheating the brakes from either braking too much and/or low pad and rotor thickness. So I would recommend checking your brakes for thickness before and after a track day and flusing out the fluid every 20K miles or every 2-3 years but not bleeding them before and after every event.

Oh, investiong in good pads, rotors and fluid is always a good idea if you are going to track your car. These are your brakes, the thing that keeps you from crashing do not be cheep or cut corners. if you do not know how to work on them, pay someone who does or learn the right way to do it. That does not mean have your neighbor teach you. Read a manual and/or take a class at your local community college.

 

WRONG!!!!!!

Freshly bled fluid is absolutely essential in your brake system before a track day. Try tracking your car with 15K mile fluid and tell me what happens. I once got lazy and went just 4 weeks between events on Motul- I had to bleed at the track as a result.

 

That is really, really bad advice.

First off, you shouldn't be bleeding your brakes before every event. You should be flushing the entire brake system with fresh fluid before each event. Given the cost of a track day, another $40 on a couple of bottles of Motul to ensure you have fresh fluid in the brakes is cheap insurance.

The typical cause of boiling brake fluid during a track session comes from brake fluid's propensity to absorb moisture, not from air trapped in the lines. If you've got air trapped in the brake lines you'll notice it the minute you back out of the driveway - you'll have a spongy, unresponsive pedal. That problem should become apparent long before you even get to the track.

Again, air is not the root cause, moisture is.

Here's why. Your braking system may be airtight once the master cylinder cap is tightened, but it isn't completely anaerobic. There is air trapped under your master cylinder cap, and that air has moisture in it. DOT 3/4 brake fluids are hygroscopic - they slowly absorb moisture from any contact with the air (like the air under your MC cap), and that moisture is held in solution in the fluid. That moisture is just plain old water, and it boils at 212 degreees Fahrenheit... a temperature your braking system will easily surpass during a track session. Once that water boils it becomes a gas, and gasses are compressible, which is why the pedal suddenly goes soft when you boil the brake fluid.

It doesn't take much moisture at all in a braking system to drastically lower the boiling point of the fluid. Compare "dry" versus "wet" boiling points for any quality brake fluid and you'll see the difference.

In short, it is a good idea to ensure that you have fresh fluid every time you hit the track. Ignoring the lifeblood of your braking system for 15k or more miles on a car that is tracked regularly is not only stupid, it's potentially suicidal.

 

the video.. http://www.youtube.com/watch?v=sx-zmGm3Kj4

he's a very luck guy

 

Glad you guys responded to that one...I wouldn't have been that nice.

What works on the street has almost no relevance on the track.

On the street your brakes will likely barely get warmed up...thats why motorsports pads that are designed for high heat situations don't work on street cars...or are so abrasive at low temps that they eat the rotors on the car.

I have found that my pads wear surprisingly even on the track. They are usually within .5mm pad to pad, and side to side. I had a sticky caliper once..that showed up hotter, and wore down the outside pad more than the inner...till I cleaned and re-lubed it.

As said above...the "bubbles" that you get in the system...that cause a soft pedal...are really water vapor that has boiled and vaporized. and the fluid near the calipers is more prone to absorbing heat and water

 

if you can't risk balling it up don't put it on the track

there are so many things that can cause you to wreck unexpectedly, many won't even be your fault such as a car dropping oil/glycol/water, etc.

I've even seen a few autox cars totalled over the years, poopy happens I was t-boned at a drag strip about 15 yrs ago ...

 

Many pads are extremely sensitive to temperature in their wear rates. If the inside of the rotor was running hotter than the outside, such as might be the case with a backing plate in place, you could run out of pad quite a bit quicker on the inside.

"Prepare to Win". Read it, understand it. Live it.

 

check list before every track event--visually check car (includes temps)before you go out on track---everytime. This lucky fellow (expensive lesson but wasnt hurt thank God) admits (to his credit) he could have done better. Interesting that the car went into failure rather than reduced mood.
If pads are less than 1/2 on a non hard brake track even---replace.
olddragger

 

Please don't ever post in this subforum again. You obviously have no idea what you are talking about. Maybe you should go frequent the bodykit area, or the putting lambo doors on your car area.

Thanks!

 

i think the guy is a tool for blaming the ABS system for his negligence on checking his brake pads

here's what they looked like, i would NEVER even think about going on the track with those pads, NEVER!

 

Maybe on the street in my DD, never on track.

 

I got a alot of flack for my coments on not bleeding the brakes before going to the track, so let me clerify. Bleeding brakes and flushing brakes are 2 different things. Bleeding the brakes means you open the lines and remove the air. Flushing the brakes means you remove the old fluid and put new fluid in, which is done by using a vacuum or suction system to remove the fluid from the master cylinder and at each brake caliper. If you only bleed your brakes to get air out when the pedel felt fine, you have done almost no good and basicly wasted your time. However, if you flush out your brake fluid, the entire system, then you are removing the old fluid which could have moisture and that is a good idea for a street car and required for track cars. This is an important destiction to make, because if your average driver who know nothing about brakes goes to his mechanic and says, bleed my brakes, he will get just that. The mechanic will open each caliper bleeder screw and press the pedel once or twice and be done. Well that did not remove enough fluid and that vehicle is almost no better off. Call it what it is, Flushing.

You are right, I do not have a lot of track experiance and my experiance is from working on street vehicles and targeted to the average driver who only takes the car to the track once in a while.

So I will change my recommendation. Before and after going to the track, flush your brake fluid, check brake rotor and pad thickness and check for leaks.

 

You still have no idea what you are talking about. Oh and thanks for your "recommendation", hopefully nobody reads your post.

 

one thing about flushing the braking system each track day. if you buy the right kind fo fluid then flushing every event is not needed. most track day guys use motul or ATE brake fluid and that is why you're having to flush your systems every event. if you were using Castrol SRF then it would only be needed once per season. guys i club race with put new SRF in at the beginning of each season and leave it for the remainder. that includes 20-30 90 minute races at VIR, CMP, Road Atlanta and Summit Point. the ITE firebird i crew for runs SRF for 13 hours without any fade issues. we have to change pads but not fluid. sure, i know it's $75-$80 a liter but when you only have to do it once a season as opposed to changing the fluid before each race weekend with motul RBF600 or ATE superblue the SRF ends up being much cheaper.

 

Two things bother me about this guy's 'problem' and what he blames for eventually giving him 'no brakes'

1. he says there are no brake wear sound clips (metal to the rotor clip on low pad thickness) on the MS3. I don't know for sure, but that doesn't sound right on any modern car. He says he's on Hawks, an aftermarket pad. The piece that's missing is attached to the pad. If he (or someone) just took off the OEM pad and replaced with Hawks, chances are they neglected to remove the device from the OEM pad that had it, and just threw pad and all away. He seems to just gloss over this...actually it appears (according to the thread on the M3 site) it never occured to him. Rather he just says the car has no such clips.

That's question #1 that doesn't quite wash clean.

2. by his own addmission he drives as described in these quotes below. This is not good driving, this is reckless driving, plain and simple.

"Another piece of the puzzle falls into place - The uneven brake wear I saw was most likely due to the amount of time i was in the ABS while braking hard during 4.5 track days. Every time the ABS pulses, the outer caliper moves slightly. Given how fast ABS pulses, a certain amount of energy being transferred to the outer pad was absorbed by the inertia of that massive piece of metal, and possibly slight flex as well. Use the ABS enough and uneven pad wear will occur. It should not be a problem on the street or on the track if ABS is not engaged on a regular basis."

"Traction control is not an issue on a road course as it might be on a drag strip. Call me lazy, but I lean heavily on ABS at the track. I know that skilled drivers can threshold brake better than ABS and I let them. For me, I like tromping on the brakes and letting the nannies figure out the quickest way to slow me down. The downside is the uneven brake wear and the unintended consequences..... The brake performance on these cars, with high performance pads and fluid, is excellent. Just please watch your inner pad wear. All that being said, if ABS had not been active, dump mode would not have kicked in and I would not have crashed. Hindsight..."

He seems like a pleasant enough 50+ yr old track guy. I'm very glad he survived his ordeal. But he's a guy with some very very VERY bad track habits and, in this case, this produced some very very VERY catastrophic results.

#2, that's not a question, but a certainty - He has POOR DRIVING HABITS - and NOT a GOOD indicator of the level of his overall driving skill or ability esp. to be doing what he's doing on track.

Even given what happened to him, it doesn't appear he gets it - EVEN after he describes his driving style. Trusting your life entirely to the car's ability to save it's and your butt under the most extreme circumstances by JUST JAMMING THE BRAKES and hoping it all works out, repeatedly, and knowingly is just plain STUPID.

THAT and proper car maintenance are what should be learned by his accident by all who track.

 

Well said.

I have managed to wear an OEM pad to the backing plate (inner right rear), and there were no wear indicators on our cars from the factory, except on the right front. Don't know about the MS3.

I was obviously very lucky since it happened during my last session of the day and I heard the scraping on my way home. My front pads, which I has assumed would be dead first, still had 4-5mm of thickness all around. I do not rely on ABS, but had attributed the uneven wear to the EBD system.

My brake inspection process has become much more thorough. I hope this guy learns his lesson.

 

Yea I've always wondered why cars don't have them on all 4 wheels, just to alert one to this type of wear. Seems like they can't cost more than a penny .... I guess every penny saved counts. As far as I can see, they are not an orderable part. I'd like to get a bunch. Maybe one comes w/oem pads?? Don't know.