posible boiling brake fluid.. pic

[Raymund]

Welp, I finally done did it. Hot lapping at Buttonwillow, I faded my brakes so bad, I couldn't induce the ABS to kick in. There weren't enough clamping force to lock up the tires.

Initially, I assumed it was mostly due to the pads (OEM) over-heating. After pitting, looking at the brake reservoir, I noticed two bubbles trapped underneath the silk-like screen. My initial thought.. it could have reached boiling point during brake fade. It wasn't actually boiling at the time I checked, but it could be a sign it was. Or, maybe it was just the fluids sloshing around during the laps that caused it? Next day, I checked and the bubbles had grown which leads me to think more bubbles found their way up the brake line overnight.

Whats anyones thought on this? Could it be just the pads or the brake fluid too?

Anyhow, I will need to upgrade the brake system now. This was something I never planned for with the GT-S. This sux.

btw.. I always check the reservoir is fully topped off.

http://albums.photopoint.com/j/View?u=1378423&a=14069128&p=57045555

[traitor]

it looks like you ran it out of fluid, I think the bubbles came from when the fluid sloshed and sucked air in. I wouldn't worry about it, just bleed the brakes and keep on truckin'.

[Raymund]

I'm leaning towards the slosh theory also. Its just hard to deny the fact I noticed the bubbles right after brake fade.

I will do a complete flush and replace it with a higher dot rating.. thats only a couple bucks.. Thanks

[autxr]

OK, first...

The GTS should never need a brake upgrade, it has more braking power than it needs.

Second: How many lapping sessions have you done? Was this the first one? How old is the car?

All the folks I know that care about going fast and braking had change their brake fluid immediately before a track day. Use something stout like Motul 600 or similar (Ford Superduty gets a lot of mention as well).

Many of these people will also bleed the brakes *in-between* track sessions. Yes, new fluid, then new fluid 2 hours later.

None of these folks (with heavier cars and less brakes) complain of brake fade.

Third: What pads are you using? OEM you said. Well, try upgrading to some that can take the heat. Porterfield R-4 (change thema t the track) or R4-S for mixed track and street.

Fourth: What are you doing to keep the brakes cool? Are you running the stock backing plates? Air can't get in to cool the brake swith those. Remove them, also run cooling ducts from the front to blow in at the center of the rotor (near the hub). This will help significantly.

All 4 of those things will help (and eliminate any problems you are having). The most expensive is a fraction of the cost of a brake upgrade.

Scott

[autxr]

Just looked at the picture, that reservoir is dangerously low. Who let you on the track with the it that low? Around here a safety inspection would have solved that.

Was it full (to the "Max" line) before the session started.

Brake fluid only goes one place if there are no leaks, that is into the void behind the caliper pistons. Low fluid means worn out pads.

Scott

[Raymund]

The brake fluid level is in between as indicated by the max/min line indicator. I'm using OEM fluid also.

The lap session lasted approx 25min. 15min within the session brake faded at one hard braking point. I hit my brake marker and the intial bite I am always getting followed by the ABS wasn't there. It took me by suprise and the rest of the time remaining I had to adjust my brake points.

Maybe you're right, there could be a lack of reserve oil. However, if it was the case I should have noticed that from the get go. The other session remaining of the day; 3 with 25min duration came on with the same gradual fade.

Also, brake pads is new just replaced it within 4k miles. It stil has plenty of life left and is approx 80% new.

As for tires I'm using 225 BFG slicks.

I'll top of my fluid to the max nextime around and will change dot rating.

Thanks Scott

[Raymund]

btw.. the event is held by speedtrialusa.

[autxr]

Sorry, the picture made it look like the fluid was really low. The air is still likely from sloshing. I suspect if you boil the fluid, it will liquify as soon as it cools, no bubbles. Not to mention, there is a bunch of line between the hot part of the brakes (the caliper) and the fluid reservoir.

Did the pedal just get really hard (more pressure did not result in more braking) or did the pedal go to teh floor? Air in the line will manifest itself by a soft pedal that goes to the floor (boiling fluid should do that too). A hard pedal (lots of pressure but no braking) really sounds to me like overheated pads (friction coeficient drops too low).

Scott

[Raymund]

Hmmm?!?! Now I'm positive it was only the pads that overheated

The pedal pressure is not what concered me. It stayed the same through out the time. It was the longer stopping distance required, and the fact the ABS should have activated due to the amount of pressure I excerted on the pedal. It was fully pressed in. Nevertheless, the pedal pressure never dropped.

Porterfeild R4... I may have to add "brakepad swap" along with tire swap in the to-do-list at the track. I never thought it would come to this with the GT-S.

[Angelo]

If you want to destroy your rotors, go ahead, use Portefield.
I'd try Hawk HPS +, they're great for the light track use.
Scott is saying that stock GTS brakes are good enough, however I've had them overheated lots of times. Brake flush and good pads definetely help, but you can still run out of brakes(ask me how I know) So what I did.....well, look at the picture. Good luck

Angelo

P.S. I can't believe I didn't make it to Buttonwillow this weekend.... I had to move. By the way I'm in Encino now, really close to Reseda( White Oak/ Sherman Way ). So I'll see you around!

[autxr]

Well, the Brembo is fine and all, but still a "show" piece IMHO.

I know folks that have done enduro's in the Celica with stock brakes, a little cooling, and good pads.

I would try the cheap upgrade first (cooling ducts, remove the backing plates and good pads).

Yes, the R4 will definately eat a rotor when it is *cold*. The R4 should only be used when driving ON track, not to and from.

The R4S will do good dual purpose duty and not hurt the rotors when cold.

The Hawke is just fine too, but I have heard of folks going head to head between the TRD pads (Hawke) and the Porterfields (R4S), and the Hwke faded, the Porterfield did not.

For ABS to engage the brakes have to lock, if the pads are fried, they may never generate enough friction to lock the tires.

Scott

[Angelo]

Scott, sometimes you're so stubborn!:) I wish you can drive my car on the race track, I can bet you could shave few seconds off your lap times. And it's no way "SHOW" mod, it's purely functional. People who want show buy AEM. I'm just not into looks. Please don't judge something you never tried! From my experience I can tell, there is no substitute for big brake system.

Angelo

[Raymund]

You both make good points. Thanks for sharing them.

Angelo, few questions about the Brembos (they look awesome, btw). Is that the 2-piece or 1-piece caliper? What was involved in instaling them? Did you run into any lack of brake oil reserve problem? Since the brembos use 4 pistons which would require more pressure on tap, will there be enough fluid in the reservoir for the brembos? last, how much?

ps. Which organization do you usualy run with? Me, TCRA, but I'm leaning towards SpeedTrialUSA as they seem to give a better deal, cheaper and more track time. Let me know when ever you head up to the tracks.

btw, my record is 1:19 (Buttonwillow west-loop) I think I can drop that a second or two with better brakes!


Scott, I agree, The R4 will out fade the TRD pads (hawke) As demonstrated by a few friends. Come to think of it, I've never heard of anyone fading the R4 yet! As for rotor wear, I've heard nightmares on both brands. If I had to choose one, I would say the R4 has the edge. It will just chew up the rotors a little bit faster than the Hawke pads.

[Angelo]

No, you don't need bigger brake reservuor. Installing them was a snap, I had to cut backing plates off though. Caliper is two piece cast and machined aluminum, with for sequentially sized pistons to minimize pad taper (36:40mm). The difference in braking is just unbelievable, I will have hard time overheating them now. Plus there is huge choice of brake pads available for this caliper, including Pagid Orange.
Rotor is one piece, 330x28mm.

Speed trial USA seems like a good choice, prices are very reasonable. U used to go to BMW SCCA events, as well as few Touring Car Club(?) events. Do you have a schedule for next year?


Angelo

[Raymund]

oops let me rephrase that question Angelo?

Do you think the brake piping/lines would be adequate, and wouldn't be a bottle next in supplying enough oil pressure to the brembo calipers (8pistons total?)

Reason I ask b/c I read a review with the Comtech S2000 having a Brembo upgrade and it actualy required a longer stopping distance due to stock brake-line delivery system being a bottle neck. It couldn't supply the increased amount of pressure required by the Brembos. I'm sure the end out come was good, but it was a compromise that was taken for braking concistency.

Also another question? do you find your ABS engaging more often with the set-up? I'm assuming the brake bias shifted more to the front wheels and causing them to lock up more frequently?

Can you recomend the place where you purchased the brembos from?

If it seems like I'm asking to much question it just I'm seriously considering the Brembos.

No, actually, I don't know their schedule for next year (speedtrial) However, they're having their last event in Dec 15/16 at LagunaSeca. http://www.speedtrialusa.com/index.htm

2002 west coast schedule...
West Coast

1. February 23-24 Buttonwillow Racepark / West Loop Buttonwillow, CA 1.86mi
2. June 15-16 tentative California Speedway (Road Course) Fontana, CA 1.5mi
3. July 27-28 Streets of Willow Rosamond, CA 1.7mi
4. August 31-1 Streets of Willow Rosamond, CA 1.7mi
5. November 2-3 Buttonwillow Racepark / West Loop Buttonwillow, CA 1.86mi
6. December 7-8 Streets of Willow Rosamond, CA 1.7mi

[Angelo]

No, there are no problems like you're desctibing. I can't really reccomend anyone since the kit is not available for sale yet, however WCT and Titan Motorsports will have it as soon as it's out. I'll see you around!

Angelo

[erok]

Ray - I figured this was you. BTW I'm back in LA. The stainless brake lines and Porterfield R4-s brake pads we put on my car work awesome together. The lines give better pedal feel alowing for more precise control and the pads grab really hard without triggering the ABS when they heat up. At Buttonwillow last summer, I had no fade at all and I was really nailing the brakes hard. I use Motul brake fluid too.

The Brembos are cool, but for the price I think my set up is a better value. The whole thing including paying to have the lines installed was about $450. That wouldn't cover one wheel of the Brembo set up!

I'm going to Hollywood Park tomorrow to give autox a try.

- Erik

[Raymund]

Eric, nice to hear from you again. Yes, I think you and Scott are right on the money.

I figured the front brembos, when they do come out, will retail for about $2500. Compared to a set of R4, extra rotors, steel lines, its still under 30% percent of what the brembo would cost.

Have fun at the AutoX.. go kick some ass!

[Angelo]

You're aiming too high!
Price will be in $1800 range...
Angelo

[SlopeSurfer]

Ran VIR both days last weekend at a Speed Trail USA event. After 240 miles at speed on a course with 3 straights the brakes held up awesome (TRD pads). Car handled the abuse great.

Met a bunch of cool road racers from Honda-Tech.com I just might buy a CRX track car and race in the Honda Challenge.

[Raymund]

wow.. there are more road racers on celica.org than i thought!!

how are ur rotors.. are they glazed or warped??

down here in the west, we have a 2.2 challenge cup that i'll probably join next season. its similar to the honda challenge, but not restricted to.

btw.. most of my track buddies are from honda-tech.

[SlopeSurfer]

Originally posted by Raymund
how are ur rotors.. are they glazed or warped??

rotors are fine, all I did was replace/flush the brake fluid before the event. Especially on the second day, I was under threshold braking from 115 to 40 or 50 (depending on the straight) twice a lap. I still haven't washed the car and my rims are black. You could have roasted hotdogs near my tires after a 25 minute run.

I'm addicted, need a track car.