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Brake question - be gentle

1446 Views 10 Replies 8 Participants Last post by  jaj, 
C
So I'm prepared to get mauled for asking this, but here we go...

I drove down to Orlando a week ago to depart for a cruise (highly recommended if you dont want to sleep for 5 days), and I noticed a scratching/ screeching sound from the front right brakes as I decelerated to pay tolls. My buddy heard it in the car several times too. Its only audible with the windows down, and it would make the noise sporadically on both braking and coasting. Well on the drive home I didnt hear it (why would you on the highway though) and kinda forgot about it.

Anywho, there is a 2-day auto-x this weekend - I got out there this morning and still hadnt heard anything. After my first run however, I heard the noise again. I inspected the front wheel - no scoring on the rotors and everything appeared to be right. Later, one of my buddies out there confirmed that he could hear it from where he was standing - mostly on left turns (when the right front is loaded). We checked it out a couple more times but couldnt find anything. Performance wasnt affected, and braking remained strong.

I ended my runs early and ran over to Meineke to have them take a look. We drove the car and he heard the noise, then he put it on the lift. After inspection, he told me that my brake pads were shot and that my rotors needed to be replaced as well. He measured the rotors and said they were just under 30 mm, and that the minimum thickness is 30.5 mm or something. I took a look at the pads myself, and they are def shot.

My question is this... would I be a total idiot to do a few runs at the autox tomorrow? I know everyone will say yes, but if I am replacing the rotor and the pads anyway, will I cause further damage - possibly to the caliper? I am going to upgrade to slotted rotors, stainless steel lines, and Axxis pads in front as well. The only reason that I'm tempted is because I was quite fast today... FTD was like 29 flat and I got down to 30.5 on my last run (and as usual I was the heaviest car out there by at least 500 lbs). People were quite amazed and I felt pretty damn good!

So... feel free to tell me I'm retarded to try to go again tomorrow. Thanks fellas.
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OK. You are retarded for trying to go again tomorrow. :haha2:

I am 100% joking with you. You did say to go ahead and say it. However, I am sure you will get some expertise here in a bit. In my opinion, I don't think you should. Not because you can ruin your braking system there. Its....once you are done...how do you get home safely?? That would be the deciding factor there. :M5thumbs:
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If your rotors are ok, I say just buy a pair of pads, take an hour to swap them out, bed them in.

If you go past the pad material and get onto the metal of the plate... g9s8r is right. How are you going to get home? You will lose all breaking really fast and might end up hurting yourself and/or other people.
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I'm a conservative type (Engineers typically are).
Quit now!
Replace the pads and rotors accordingly and then, and only then, go back to the track.

Al. Wise
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+1
I wouldn't suggest driving the car on the road till you get the brakes and rotors replaced. Your front brakes are your main braking power. they may feel strong, but once you are metal to metal, you are not going to be stopping that beast. Granted the only thing you will damage on the car mechanically is the rotors and pads, but at the point were there is no more material on the pads what so ever, you will be damaging not only the front of your car, but possibly yourself along with whoever is in front of you at the time. Say a kid comes out in front of you chasing a ball, you slam on the brakes and the car doesn't stop due to failed maintainance that you knew about. Is any track event really worth what can happen knowing those brakes are done? Could you handle the knowledge of what can happen because you wanted a little fun. Be safe! End of story.
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cheerIO said:
If your rotors are ok, I say just buy a pair of pads, take an hour to swap them out, bed them in.

If you go past the pad material and get onto the metal of the plate... g9s8r is right. How are you going to get home? You will lose all breaking really fast and might end up hurting yourself and/or other people.
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+1
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ccm241 said:
My question is this... would I be a total idiot to do a few runs at the autox tomorrow? I know everyone will say yes, but if I am replacing the rotor and the pads anyway, will I cause further damage - possibly to the caliper?
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If you install new pads you should be fine. The limit on rotor thickness is set to ensure that the piston don't extend too far out of the caliper when the pads are worn out. If you have new pads, the thin rotor isn't optimal but it's ok, and the pads are thick enough not to stress the caliper piston.
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A couple things to keep in mind.

If your pads get down to metal, and the metal gets too thin, you could lose the pad backing, and then have the caliper piston on the rotor.

Check your brake fluid also, as the pads get low, the fluid in the reservoir will drop, if it drops too far, bad things could happen.

These are worst case scenarios, but it's not a risk worth taking.
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jaj said:
If you install new pads you should be fine. The limit on rotor thickness is set to ensure that the piston don't extend too far out of the caliper when the pads are worn out. If you have new pads, the thin rotor isn't optimal but it's ok, and the pads are thick enough not to stress the caliper piston.
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A too thin rotor will also be more prone to cracking, if they are out of spec, then I wouldn't risk running them on a track
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So I didnt do any autoxing on Sunday, and have pushed back my track day til March. I just ordered Stoptech stainless steel brake lines, axxis ULT pads, and Motul fluid. I figure thats a start. Next step will be to add the 345 x 32mm slotted sportstop rotors. Will it be possibly to add the calipers later to complete the full BBK?
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ccm241 said:
So I didnt do any autoxing on Sunday, and have pushed back my track day til March. I just ordered Stoptech stainless steel brake lines, axxis ULT pads, and Motul fluid. I figure thats a start. Next step will be to add the 345 x 32mm slotted sportstop rotors. Will it be possibly to add the calipers later to complete the full BBK?
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No. The Stoptech BBK is totally different than stock - no parts are interchangeable. Rotors are 355 mm instead of 345 mm. The stainless lines are different - the BBK ones have a banjo fitting to the caliper while the stock ones are threaded both ends. The pads are quite different. The only things that don't change are the caliper and rotor mounting bolts - everything else is replaced.

It's not clear you'd need a BBK for auto-x though - you should be fine with the stock brakes - if you get overheating change to a Hawk HT-10 racing pad in the stock calipers.
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