how much abuse before your brakes fade?

[MyBeatGSX]

I made two 90-0 stops in a period of 2 minutes and my brakes were trashed. Half way through the second stop the pedal started getting soft and I layed into it hard and didn't even have enough bite to engage the ABS. When the car finally stopped it smelled like horrible toasted brake pad and the pedal was mush. After sitting for probably less than a minute, the pedal feel was rock hard again but the pads stilled smelled horrible. I made an 80-20 stop a few minutes later while the pads still smelled, the pedal feel was fine during and after.

I want to know if this is normal. I realize these car are heavy, but 11" vented rotors aren't exactly undersized. I also have VGX pads (not sure how good those are) which have made no improvement over my worn stockers. This car has by FAR the worst stopping ability of any I've driven. Or maybe that's purely perception because it can hit far higher speeds on the same roads than most cars its size/weight.

BTW, I find this all odd in the light of another fact. I had a messed up front left brake that dragged while driving. I didn't know about it and took the car on the highway for 15 minutes. When I parked, the brake was smoking. However, even in this extreme heat (far hotter than I got it this time) the pedal feel never changed the slightest bit. In fact the hotter it got, the harder it grabbed.

 

[DSMunknown]

Perhaps this may help you out:


http://miata.net/products/perform/vgx.html

 

[FORMONTOYA]

Just a general statement. I haven't really tested 100-0 type braking, but here goes:

I know that my car with OEM brakes (10.1F/10.3R) sucked.....maybe one good stop at speed was all they were worth, if that.

Switched to EBC Greens plus braided lines.......cold bite was about the same as OEM. However, once they got some heat into them they were remarkable. Quite a noticeable difference in stopping power. The problem is that the small rotor could not dissipate the heat fast enough and started to crack the front rotors.

Switched to PowerSlot Plus rotors (11.7F/11.5R), stayed with the EBC Greens and braided lines...........just flat amazing. Really the same cold bite as before, but when the brake get some heat in them........look out! The only thing I had to get used to was that the brakes are loud running the slotted rotors, plus you have a little "feedback" from the pedal. But "boy howdy", these thing shut this heavy boat down.

Haven't tried them yet, but the only thing that could be better would be a set of "real" big brakes....bigger rotors, bigger calipers. That should put you through the windshield.


But yea, A 3000+lbs car with tiny 10" rotors = not stopping under extreme conditions more than once.

 

[DSMunknown]

Jim, when you speak of getting some "heat into them" do you mean spirited driving, or would normal stop-and-go traffic and suburban driving do the trick? Or do you mean the EBCs are most effective in track-like driving (something more punishing on the brake system than the normal spirited driving)?

 

[FORMONTOYA]

Stop-n-go traffic helps as it does build up heat, however, at slow speeds it does have a tendency to not heat up much and dissipate rather quickly.

I was mainly talking about "spirited" driving. That's where you build up and retain some heat.

But to reinterate.......the EBC Greens work nicely even cold (IMO), as good if not a little better than OEM.

 

[Quasimondo]

There are two main contributing factor to brake fade. The first one is old/bad brake fluid, the second is not so good brake pads.

As brake fluid ages, water will be absorbed by the fluid. Under normal brake use, this is not as big a problem. Under heavy use when the brakes get hot, however, this can be a problem. As the brake fluid heats up, the water that was absorbed boils, creating air bubbles in the brake lines. When you apply the brakes, these air bubbles get compressed before that pedal energy transfers to the brake pistons. The easiest solution: Flush and replace your brake lines with DOT 3 or DOT 4 brake fluid. Don't bother using DOT 5 fluid. A quick search on Google will show you that while DOT 5 seems better than DOT 3 or 4, it's more hassle than it's worth.

Brake pads is your second contributor and is more commonly assumed as the problem when it comes to brake fade problems. This occurs when the brake pads become overheated. Overheated pads create a layer of gas that sits between the pad and the rotor and the pad 'floats' on this rotor instead of creating the friction needed to slow the vehicle down. The solution: Higher quality pads that have a higher operating temperature (and will not overheat and vaporize as quickly), combined with drilled or slotted rotors that allow any built up gas to escape (preventing the pads from floating) when a brake pad does overheat.

Based on what you described, I think your problem might be with the brake fluid. If you haven't flushed it out and replaced it in over a year, do so. Brake fluid absorbs water quite easily and should be flushed out and replaced as part of your yearly/seasonal maintenance.

 

[FORMONTOYA]

^^^A great point about the fluids I forgot to mention. It does need to be replaced at a regular interval (and maybe sooner dependant on driving habits) same as motor oil and the like. A Motive pressure bleeder does wonders.

 

[MyBeatGSX]

Mine is probably original... might be time to do that...

And I guess the crappy quality of the VGX pads explains why they baked almost instantly. Must...research...before....buying...

 

[Defiant]

As brake fluid ages, water will be absorbed by the fluid. Under normal brake use, this is not as big a problem. Under heavy use when the brakes get hot, however, this can be a problem. As the brake fluid heats up, the water that was absorbed boils, creating air bubbles in the brake lines. When you apply the brakes, these air bubbles get compressed before that pedal energy transfers to the brake pistons.

Y'know, along with the stories of turning brake discs, this is another tale we hear whenever brake maintenance is discussed. And yeah, I have no real challenge to most of what people who want to get money from my wallet have to say. They even make test kits that have a paper strip you can dip into the master cylinder's fluid and prove that the fluid's shot..... or, at least the fluid in the master cylinder resevoir is.... which has that nice little vent in the top of it, exposing air and its moisture to the fluid every time the pedal's pushed. And the fluid in the system may be moving a half-inch when the brakes are applied, so you have those few ounces moving back-and-forth. But most of it, such as the fluid actually in the calipers, is shielded from the atmosphere by a goodly amount of buffer.
Now, I don't know how much gets past the caliper seals, or manages a molecular migration through the flex hoses, nor how much diffusion goes on from the master to the cylinders. And yes, brake fluid does get contaminated and lose its heat-defeating capabilities.
I just wonder sometimes about all the tales we're told by the marketing department.

 

[steve]

Did you bed these pads and rotors when you did the brake work in August once you finally fixed all your problems?

Steve

 

[MyBeatGSX]

Bed them in how? A few back to back pedal to the floor stops? Yes.

 

[jtmcinder]

or, at least the fluid in the master cylinder resevoir is.... which has that nice little vent in the top of it, exposing air and its moisture to the fluid every time the pedal's pushed.

Actually, the vent is on the far side of the black bellows, allowing the bellows to move with the fluid while isolating the fluid from the environment.

- Jtoby

 

[boosted_91_tsi]

My brakes grab great anytime I stop. Stock calipers, stock lines, stock size rotors, Hawk HP+ pads, and Ford heavy duty brake fluid. I originally got the pads for autocross and when I laid into them on the course I nearly rubbed the front tires on the fender. I am not sure how great it is to use these pads as an almost daily driver but I have never had any problems. I also replace my brake fluid at least twice a year. I have never had them smell bad or burn and my pedal has never gone to mush even during an event. I have also had this set up for almost a year now with more than half the pad life left.

 

[DSMunknown]

MyBeatGSX, whether you realize it or not, because you have the dual-piston calipers you are actually not promoting the common upgrade what us one-piston people seek. The two-piston upgrade is supposedly known to be a significant improvement over the one-piston, and you don't seem to like it very much (of course, you don't have to upgrade to it because you already have it).

 

[daren_p]

Alot of people say the 2 piston awd brakes are more then enough, just need to upgrade to a more agressive pad & change that fluid if you haven't done that recently. I went with Dot 4 as it has a higher dry & wet boiling point compared to Dot 3. When you go looking for fluid you will notice both a dry & wet boiling point listed on the bottle, while there is a min that has to be met to meet the Dot 3 or Dot 4 classification, depending on the brand the actual values will vary. SS lines will also help to firm the pedal up, but won't do anything as far as brake fade goes.

Personally with my fwd setup, the rotors worped quite quickly & a firm stop from 60+ mph would result in the pedal mush & smell you explained. I went with a Wilwood 12.2" rotor & 4 piston caliper setup & let me tell you this thing stops crazy now. High speed stops are no problem, haven't experienced any brake fade & I've tried pushing them. First time I wanted to see how they worked at higher speeds, I went to do a firm stop around 100 mph & they locked up (don't have abs), must saw, woke me up quick . Just to compare, when my car was down for 2 weeks I was driving my old mans 95 vette, defently no slouch in the braking department but when I got back in my car, it was a good thing I wear my seatbelt as I kept trying to put myself through the windshield every time I stepped on the brakes I just picked up some powerslot rotors & Hawk HPS pads for the back, not that the rear brakes do all that much, but it should complete the brakeing package nicely.

Bedding in is very important, you want to make 5-10 slow downs from say 35 mph to about 20, with about 20 seconds after each one for cooling time, then repeat from 50 to 20 mph, with the same amount of cooling time, then finally repeat from 65 down to 20, with once again the same amount of cooling time. Continue to drive for another 5 min or so without using the brakes to let them naturally cool down. Then park the car & let them fully cool till you can touch them & you should be all set. It is very important not to come to a complete stop while beding pads.

 

[prostreetdsmx1]

SS lines, quality fluid and good pads will do wonders! Ultimate Ceramics, Hawk HPS and HP+ brake pads are my personal favorite options. I highly recommend the Technafit Teflon coated SS brake lines and ATE or Motul brake fluid. PROPERLY BLED!!!!

You would be amazed what these products will do for your braking. That's why we use them in our kits. Hell my old 2g having brake issues is what got me to put these kits together in the first place. That damn 2g FWD could fade and lose pedal pressure like a SOB. Never again!

 

[MyBeatGSX]

Thanks for all the help.

prostreet, thanks I'll look into those parts. I need something because its hardly even safe as it is.

 

[DGajre777]

It takes me eight 80-0 MPH stops before my brakes fade. I tried it once on the interstate at 4 AM.