Here's my dilemma:

My '94 Hatchback with ABS, under normal driving, and auto-crossing, never has a problem with the brakes. I have 4 wheel disk brakes (basically the integra's setup) with slotted rotors and porterfield R4S pads all the way around. I have the integra 1" master cylinder and SS lines. Also, I'm running ATE superblue brake fluid.

My issue comes up at road courses. After a weekend of roughly 6-8 hours of track time, my brake pedal sinks and won't come back up. I've flushed the fluid but it doesn't get any better.

The last time this happened, I adjusted the pedal endplay to bring the pedal back up. This isn't going to work again since the adjustment is as far out as it can get and still work safely.

One thing I do need to note, is that the suspension changes I've done this year have allowed me to carry some ridiculous speeds though turns, and I've effectively made my brakes ineffective. I know I need more brakes to accommodate that, but I still need to address the issue of the soggy pedal.

What I'm wondering, is if I'm damaging the MC with heat or repeated heaving braking. Will the bigger brakes, generating, or at least dissipating the heat more effectively, keep the heat away from the MC, and prevent it from getting soggy or do I need to look into some kind of aftermarket solution?

Any thoughts or ideas would be greatly appreciated.

Thanks,
Alex

 

Your problem is here:

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">porterfield R4S pads </TD></TR></TABLE>

 

Please explain. I love these pads and even with the soggy pedal, braking is excellent.

 

They are street pads (that what the "S" in R4-S means) that have no business being used on a road course. They may be a great street pads, but they cannot take the heat of a race track. The "sogginess" is likely glaze from the excessive heat. That or you've bent the inner plate.

I recommend separate sets of pads for the street and track.

 

I realize the S is for street.

The glaze makes sense. I thought a fresh bleed took care of the pedal rather than the spare pads that weekend.

What is the "inner plate" you are referring to?

Thanks!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">What is the "inner plate" you are referring to?</TD></TR></TABLE>

The brake pad that is on the inside, against the caliper piston. If it bends from the temperature and presure it's subjected to under track conditions, you will get a lousy pedal feel. But my 1st guess is you way exceeded what those pads can do. A good, and I mean really good, street pad is good to maybe 800-900F tops. You can easily see 1100F+ on a road course. Especially if you still have the factory splash shields installed (I also refer to them as heat retainers) and no other means of cooling.

 

Carbon Kevlar baby!!! Come on Matt, they're not that bad.. Actually, I used those pads on my turbo R for a weekend at Blackhawk Farms. They were good enough, felt a little glazed but not monstrously bad.

Brake pedal sinks and won't come back up? I'd blame the MC.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civicgsr &raquo;</TD></TR><TR><TD CLASS="quote">After a weekend of roughly 6-8 hours of track time, my brake pedal sinks and won't come back up. I've flushed the fluid but it doesn't get any better.</TD></TR></TABLE>

Matt's the *expert* here, but I'm wondering if he skimmed that part?

Lemme guess what happened.. You had been autox'ing for a while, the car doesn't get it's brakes bled very often, and some grime built up on the ouside of the MC cylinder near the botom of the pedal's travel. You get into HPDE, start flushing brakes more often, and you kill the seals on your MC by rubbing them along the crud that built up in your 10+ year old car

Anyhow, just a guess, but I'd strongly suggest M/C is the issue. If you can set your foot on the pedal and it sinks, or it doesn't come back up, that's gotta be it.

IMO.

-Chris

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MaddMatt &raquo;</TD></TR><TR><TD CLASS="quote">The brake pad that is on the inside, against the caliper piston. If it bends from the temperature and presure it's subjected to under track conditions, you will get a lousy pedal feel. </TD></TR></TABLE>

I think he means something like this, if you like pictures (See pads in hand, which "bent" around the brake piston.

http://www.we-todd-did-racing....x.jpg

 

Actually, you guessed wrong

I have been autocrossing for quite a few years, but when I swapped my engine, I did the steering rack and MC at the same time. Since I've done that, about 3.5 years ago, I've regularly swapped the brake fluid, and have been doing so more frequently since I installed speed bleeders.

As for the pic, I didn't bend my pads, but I have pads that look about as bad as those!!

You've definitely given me some good info to think about. It makes a great deal of sense. I appreciate your time!

Given all that, what pads would you recommend? Porterfield R4's? Something from Carbotech?

Thanks again guys! You've been a great help!

-Alex S.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civicgsr &raquo;</TD></TR><TR><TD CLASS="quote">Something from Carbotech? </TD></TR></TABLE>

Yep

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Blackhawk Farms.</TD></TR></TABLE>

Dude, I wouldn't drive *to* Blackhawk with R4-S, much less on the track...

Maybe Honda masters are krap. I've never ever had a Nissan master go bad. So that's never where I start my troubleshooting.

Do this: Swap in new pads of some variety. Even an older set of street pads you know to be fine. If your pedal problem goes away, there's your answer. If the pedal still sucks, look at the master.

My bet is the R4-S pads are wayyyy cooked and glazed and that's your problem....

 

a brand new sanyco m/c for your car would be like $68.70 shipped online. i bought one and installed it for my 94 civic ex abs coupe; it works great along with the technafit ss lines. the m/c brand new too, not rebuilt. sure beats the dealer for a new m/c.

from what i know, sanyco manufactures major hydraulic parts, namely brakes, to many japanese OE companies.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civicgsr &raquo;</TD></TR><TR><TD CLASS="quote">
The last time this happened, I adjusted the pedal endplay to bring the pedal back up. This isn't going to work again since the adjustment is as far out as it can get and still work safely.</TD></TR></TABLE>

never do that to fix a sinking pedal.

i'll give you 10:1 odds that you've still got air in the rear lines and/or the ABS actuator.

ditch the speed bleeders, bleed the whole system properly, including the ABS actuator, and reset the pedal end play. then test for a bad mc. the mc in one of my cars has 260k on it. the one in the other car i replaced because i thought it was bad. turned out, i hadn't gotten all the air out of the rear lines.

get some carbotech xp8's/1108's and stop screwing around with crap street pads.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by solo-x &raquo;</TD></TR><TR><TD CLASS="quote">never do that to fix a sinking pedal.

i'll give you 10:1 odds that you've still got air in the rear lines and/or the ABS actuator.

ditch the speed bleeders, bleed the whole system properly, including the ABS actuator, and reset the pedal end play. then test for a bad mc. the mc in one of my cars has 260k on it. the one in the other car i replaced because i thought it was bad. turned out, i hadn't gotten all the air out of the rear lines.

get some carbotech xp8's/1108's and stop screwing around with crap street pads.</TD></TR></TABLE>

For the sake of experimenting, I picked up some $20 pads and threw them on. My entire problem was the pads. They were definitely glazed.

As for adjusting the end-play to correct the pedal; I agree, that's not the right way to do it. It was nice, however, to bring the pedal up to make it easier for me to heal and toe (the way I do it)

I do recall, in my earlier years, having quite a bit of trouble getting the air out of the rear lines. I even remember thinking of replacing the MC as well. I've been able to do a decent job of it, but it wasn't until I installed the speed bleeders that I was able to flush the brakes quickly and effectively. Why do you have a problem with them?

thanks for the suggestion on the pads. It's painfully obvious that it's time to set up to some racing pads for the track. I'll keep the street pads on the street.

-Alex

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MaddMatt &raquo;</TD></TR><TR><TD CLASS="quote">Your problem is here:
porterfield R4S pads
</TD></TR></TABLE>

absolutely!

 

i've heard of many problems that were finally attributed to speed bleeders. if they are working for you, then by all means continue.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">I picked up some $20 pads and threw them on. My entire problem was the pads. They were definitely glazed.
</TD></TR></TABLE>

You're welcome

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MaddMatt &raquo;</TD></TR><TR><TD CLASS="quote">You're welcome </TD></TR></TABLE>

Your help has been greatly appreciated! Granted, I smoked the $20 pads driving home from work, but you'll have that

Thanks again!
Alex

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by solo-x &raquo;</TD></TR><TR><TD CLASS="quote">i've heard of many problems that were finally attributed to speed bleeders. if they are working for you, then by all means continue. </TD></TR></TABLE>

I see. I did have a problem on my 240. I couldn't get them tight enough to keep them from leaking. With the Aluminum Z calipers, I was afraid to strip out the threads.

-Alex