thebrander

Suppose during a high speed stop, one's brake pads were heated beyond the designed operating temperature range and "friction fade" kicks in, would it help to very briefly let off the brakes to allow the boundary layer of gas to escape and then get back on the brakes? Or would there just not be enough time for the brakes to cool and the boundary layer would quickly reform? I assume you would also have to do this smoothly enough to not seriously upset the balance of the car.

AU N EGL

Once you fell that " fade" pray.
Your going into the wall, grass or tires.

Time to slow down, and come in. Bleed your brakes and check your pads.

What many ppl do BEFORE they get to the 5 marker, is to quickly left foot touch the brake peddle to see IF they still have brakes. ( this is that quick flash of the brake lights seen once in a while )

VetteDrmr

What I've done the couple of times I've experienced fade, I braked, got off the brakes, made part of the turn into the corner, straightened, braked, off the brakes, turned, back on, etc.

Totally ruined the corner, but at that point I cared absolutely ZERO. It did keep me on the track.

I don't think trying to release the "boundary" layer, or shedding heat, by temporarily releasing the brakes has enough time to do anything.

The other thing I'd recommend is to back off a bit. This is for FUN, right?

HTH, and have a good one,
Mike

magnetic1

What he said... sorta. You arent going to have brakes one minute and have none the next. The symptoms will present themselves likely the corner before or earlier. Releasing the brakes wont do anything. Try to scrub off speed with downshifting (as u should do), turn, etc. If you arent going to make it, go off straight!

Tapping the pedal at 5 isnt necessarily to check for fade. It is more to make sure you dont have pad knockback.

You shouldnt be getting pad fade if you are running the proper pads. So make sure if you go on track, get a proper track compound. None of that "fits everything" type of HP+, AX6, etc.

AU N EGL

the one time I had brake fad I was going into a corner at 135 mph, hit the brakes and

the bake peddle was hard as a rock.

Let off the throttle, pumped the brakes and drive straight off, ( lots of run off room)

When car slowed to 80 or so I started a wide circle and that slowed the car down more.

Got back on the track and drove to pitt in and into the paddock

Jacked the car up took the wheels off, and removed the brake pads.

Pads were Glazed over like a fresh Krispy Kream ( Hawk HP+ pads and ATE Super blue )

Flushed the brake fluids and put on my old OEM Z06 brake pads and slowed down a bit for day two.

davidfarmer

Pad fade will come back on its' own (does not require bleeding), but it won't come back in time to make the corner (if it's catastrophic). However, you usually feel it coming on during a session, and can either back off a few braking zones, or cut the session short. If you are overheating the pads session after session, you need a hotter pad for that track. Of course that means more cooling, more rotor wear/cracking, etc.

Many people blame fluid when the brakes fade, but it is often the pads that go off. I personally rarely have ever boiled fluid, but I tend to 1.use good fluid 2. bleed at correct intervals 3. not use the brakes unless you need them (no "planting the nose", touching when you could coast, etc). I have had pads let me down occasionally however, and the only real solution is to go to a hotter pad or slow down.

John Shiels

down shift hard if it is bad and scrub speed..

davidfarmer

this post assumes a catastrophic, heat related failure, which again isn't the way pad fade happens in my experience. Unlike boiled fluid, it is more linear and predictable.

Bill Dearborn

On my 86 with stock brakes and pads it would occur at the end of the third lap at Watkins Glen (at not a very high speed). Going into the ninety the pedal would be solid but the brakes did not slow the car very well. First time it happened my instructor was yelling into the intercom "more brake, more brake, more brake, etc. I was pulling on the steering wheel and shoving on the pedal and yelled back "thats all there is". Somehow, I made the corner. After cooling it for a lap (3.4 miles) the brakes felt better, however, after the session when the pads were pulled it was obvious they were no longer usable. Completely glazed. The next year I went to the later C4 big brake package and those problems dissapeared.

Bill

63Corvette

I race a much, MUCH older car than you. However, trust me on this, TOTAL brake failure DOES happen even on the most modern cars (see Jaques Villeneuve F1 carbon disc failure). In my vintage race career I have seen my #63 car, the #6 car, The #614 car and the #97 car (Cobra) have sudden catastropic brake failure at speed. Please see the posted video and still pics of the 250 TR which suffered total brake failure at Laguna Seca this August. Now I rode around with the Skip Barber school instructor leading a Group 7 (CanAm) field in practice in a Porsche 911 on street tires and pads!!! I noticed that my driver reached the point of brake fade early in our (20 minute) session, and while talking on his radio, talking to me, and driving faster than I lap in my racecar, he routinely tapped the brakes before every corner, every time! It was actually pretty confidence inspiring to see that HE wasn't the least worried by the fact that we didn't have any brakes.........while 10 CanAm cars took turns running right up our tailpipes...every turn

davidfarmer

His question specifically asked about "pad fade". Other failures are much more catastrophic

SIK02SS

just put your foot down harder and pray :o

Cal Speedway has some serious brake zones, but i tell you what...I don't think I've been more scared as I was while going into T-11 at Infineon this year in the T1 car. Turns 4 and 7 were just as bad, but at those 2 corners there at least isn't a wall looking straight at you

Holy no brakes every lap batman

0Anthony @ LGMotorsports

Depends on exactly what is failing in the system.

If you get it hot enough that the fluid is boiling, and gasing off in the caliper then the pedal goes to the floor and a quick bleed is needed. Sometimes if you catch this soon enough you can back off for a few laps and let the fluid cool down and the pedal should start to come back.

If you get the caliper hot enough then you just start to get a long pedal, and this will change with the temperature of the caliper, but will at some point stay that way because you are going to loose the heat treat of the caliper and it will just start to flex.

A typical resin based brake pad, if you cook it past it's temperature range you will probably see either first a layer of un-even pad material on the rotor which leads to the typical 'warped rotor' and you feel a pulse in the pedal. A new, or cleaned set of rotors will fix this.

If you just have no brakes then typically you have a glazed surface of the pad, and at that point they are just ready for the trash can if it is a resin based pad as the material holding the pad together has been cooked throughout the pad and there is no way to recover them.

Sintered pads, like Cobalt will not do this because the material itself is actually what is holding the pad together.


There is more to it than this...but that is the 'quick and dirty' answer.