The past few track events i've had problems with the brakes on my car - inconsistent pedal feel and often times inconsistent stopping power (causing an Off in T3 @ VIR). Sometimes the pedal feel will be very soft/mushy and other times it will be "right there". It was somewhat predictable @ VIR - mushy in 1 and 3, 'right there' in 4, 'mostly there' in 7, and 'right there' in 14 and 16. I've been through pads, rotors, fluid and it has not fixed the problem at all.

The problem does not exist at all, in any form on the street even when i ride the brakes *really* hard (which probably isnt close to the abuse they see on track, as its hard to do 100-45 stops on the street alot). Off the track they work 100% as expected. Its only on track when they get really hot does the problem surface.

Today i went into Advance and ordered a set of OE Reman front calipers - should i look into replacing the M/C and/or Booster? I would think that if i had problems with either of those i'd have issues on the street as well.

TIA,

RJ

 

A failing wheel bearing can cause knockback under lateral load - sometimes your brakes are your first clue about the bearing.

That's all I can suggest that you haven't thought of already.

Scott, who knows how much you want to depend on your brakes....

 

well, I was going to guess the M/C &/or booster, but you're right -- you'd have problems on the street as well if that were it...

I don't know Saturns from shine-o-la, but I imagine they have a dust shield by the inside of the front rotors. Do you still have these on the car, or did you remove them? Sounds like you need to figure out a way to cool down what you've currently got, or switch to other parts that handle the heat better... or both...

 

Hi,
What pads are you using?

 

I have been using Panther Plus, and Panther XP's on the track, same result. No dust shields (heat retainers), rota Attack wheels (plenty of open area for cooling) and home depot $8 dryer tube ducting. I'll swap calipers and flush fluid again before SP and hope this works..... should i just replace the M/C as well?

RJ

 

Before you go replacing the M/C...

Are you noticing any loss of brake fluid? Is the M/C leaking? Are any of your brake lines pinched?

Not that I know a lot about brakes, or anything mechanical for that matter, but I have had to replace a M/C and it's bloody expensive. I'm just trying to give you some ideas that might save you some money.

 

no leaks, no pinched lines...

 

do you find any/lots of air in the brake lines when you bleed them after a track event? suggesting that air is being drawn into the system somehow...?

 

everytime i bleed them out, i get a few bubbles, but nothing more than expected.

RJ - stumped in VA

 

Like Scott said, I'd check the items that would cause vibration (bearings/hubs/caliper slop) - looking for something is knocking the piston back off the backing plate.

 

I have been chasing some similar issues on another non-Honda.

Suggestions: (1) make sure that the pads are not binding in the pad carrier due to expansion from heat. You would probably see some irregular wear (which contributes to the pedal inconsistency). I grind down the tabs on all my track pads where they touch the brackets for a little extra clearance. And (2) try different pads. I had similar inconsistency with my one set XP pads.

 

Pad carrier? Meaning, caliper, or bracket?

When i pulled out my pads i noticed that they were *not* worn evenly. One set was worn more than the other although i could not tell whether they were one side or the inboard/outboard of each side (although i'd bet it was just one side). Anothe reason for the caliper replacement....

Scott has had 'problems' (i.e. inconsistency) with all of the sets of XP pads he's run, which is why i decided to throw in the P+ i had in my toolbox as my backups - this helped the issue some, although did not cure anything.

Which tabs do you grind down, and where? On the pad side (friction material) or the backing plate?

Thanks!

RJ

 

What kind of fluid are you using? if your using generic pep boys fluid, it might be boiling but if your not getting many bubbles when you bleed your brakes i dunno.

 

If the pads are not worn evenly you have caliper issues. Are they single pot (floating) calipers? If so, sounds like your calipers are binding to me. Do you grease the slides every time you change the pads? Do they slide freely?

If they slide freely, it wouldn't hurt to clearance the pads a little like Mike suggested. If they don't slide freely you need to fix that.

All that being said, if the brakes go away at the same corners every lap, I'd suspect you have a heat problem. Can you get real vented backing plates for your car?

Knockback will cause you to have a long pedal, but wont actually affect braking performance.

Joel

 

Thanks for the replies... i'm gonna put in new calipers, i'll clean and l00b the pins again when i do it...

RJ

Edit: I'm using ATE fluids. When i run out of it, i'll switch to Andie's Cobalt fluid.

 

Since backing plates are stamped, they typically have a particularly sharp edge on one side. This can cause them to bind if the clearences are slim and things get loaded a little sideways (axially?) or if there is caliper flex. While I have never actually increased the clearence I HAVE chamfered the edges of the pad (we called it "blueprinting" them ) to eliminate this risk.

Kirk