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Discussion Starter #1
I still have my original brake components on my 16,000 mile Bullitt. I ran my car at Road Atlanta recently and experienced quite a bit of "brake rotor/pedal feedback" thru the steering wheel when the brakes got hot. Once they cool down the "feedback" goes away. Can anyone tell me if this is normal or if perhaps there is something that requires attention with the rotors or pads.

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maybe your caliper(s) are starting to "lock" up and are dragging on the rotors a little, this would lead them to hot and maybe you are getting a little bit of brake fade? Sound like you a pulsation issue though. I would replace the brakes and rotors and make sure that the caliper pistons are moving correctly.. remember to use grease on the slides and pins when you install everything again.
 

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There are three weak links in the Bullitt stock brake package if you're considering open track use: pads, lines, brake fluid. The stock pads are not meant to heat up like track pads. You are greatly exceeding the heat range of the pad. Many people use something like Hawk HP Plus pads as they are suitable for street and moderate track use. Be sure to bed them properly if you switch pads. Also, a higher temp brake fluid like Motul RBF600 is highly recommended. This will easily work at the track and will be just fine on the street. Lastly, change to SS brake lines. The stock rubber lines expand a lot when the fluid gets hot, air accumulates, and contributes to fade. The stock calipers and rotors are just fine for the track. In fact, many people upgrade to the Bullitt/Cobra rotors and calipers for track use.
 

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Discussion Starter #4
Thanks

Thanks for the input gentlemen! I forgot to mention that I did replace the stock brake hoses with braided steel lines and I did flush and bleed the entire brake system 6 months ago. I think that I will replace the pads though with the Hawk pads as mine are close to %50 used up. Would it be OK to just replace the front pads or should I do the rear as well, and do shops still "turn" rotors?

Thanks again.
 

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Just what do you mean by "feedback"? Is it the ABS engaging?

I have braided lines fresh hi temp fluid runing stock(PBR)pads at a local track and with no issues at all.
 

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Discussion Starter #6
"feed back" is defined as a pulsating/vibrating steering wheel under hard braking application. The car does stop very well however. I did not experience "feedback" like this when the brakes were new.

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punk lancelot said:
There are three weak links in the Bullitt stock brake package if you're considering open track use: pads, lines, brake fluid. The stock pads are not meant to heat up like track pads. You are greatly exceeding the heat range of the pad. Many people use something like Hawk HP Plus pads as they are suitable for street and moderate track use. Be sure to bed them properly if you switch pads. Also, a higher temp brake fluid like Motul RBF600 is highly recommended. This will easily work at the track and will be just fine on the street. Lastly, change to SS brake lines. The stock rubber lines expand a lot when the fluid gets hot, air accumulates, and contributes to fade. The stock calipers and rotors are just fine for the track. In fact, many people upgrade to the Bullitt/Cobra rotors and calipers for track use.
RIGHT ON, PL! I do several open track days each year and totally agree.

Auto Zone's Performance Friction pads are very good too. I have used them and they are actually a little better when they get hot. These pads are recommended by Scott Hoag.
 

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You might have some slight thickness variation or warpage of the rotors that gets worse as the brakes heat up. Take the rotors by a good shop and have them turned when you install the new pads and that should clear up. Emphasis on *GOOD* shop. You don't want them to come back with a record player finish. A brake lathe is only as good as the operator. Have you ever walked into the parts shore and heard a loud squealing/moaning EEEEEEE! type noise coming from the back of the store. That wasn't someone getting a bill, it was actually the idiots attempting to turn rotors without the anti-vibration strap wrapped around the circumference of the rotor and trying to cut with burned up cutting inserts. I bought my own inserts and vibration damping straps when I was a tech to make sure my jobs all had a good finish on the rotors.
 

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One more thing: when you get off the track and the rotors and pads are hot - NEVER EVER use the parking brake. Put the car in gear when you shut it down or keep in neutral and chock the wheels. This is a sure fire way to mess up your rotors.
 

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GREAT TIP! Thanks for mentioning that point. The pads act as a heat sink, so if you park it while hot, the rotors will warp because the rotor will cool at a different rate at the location of the pads contacting the rotor.
 

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I agree it sounds like warped rotors. They may be able to turn them, but best best would be to just replace them. They are not expensive
 

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Bullitthead Ag said:
GREAT TIP! Thanks for mentioning that point. The pads act as a heat sink, so if you park it while hot, the rotors will warp because the rotor will cool at a different rate at the location of the pads contacting the rotor.

At the road course it is general knowledge that parking the brake should not be applied. Just leave it in first gear.

However, as the brakes cool in the pits no one seems to be concerned about moving the car so that the pads are not left in the same position relative to the rotors.
 

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Brakes Pulsating at Track

First time I went on the track, I had some vibrations like warped rotors, and it totally cleared up during the first heat. Spectators said dust was coming off my wheels during braking for the first 3 laps and then no more. Brakes worked good.
My setup was stock pads and brakes. I left the car running in the pits after the first race and had no brakes when I went to move it later. I pumped them up and was good for the rest of the day, must have boiled the brake fluid.
The next year, I used higher temp fluid and SBS pads in front and Hawks in rear and had no problems. Leave the car running and as stated, parking brakes have plastic parts that will melt. I think he stock pads allow dust to build up on the rotors whick caused the feedback you speak of. I cleaned mine up a few times in the past on good pavement with many 60mph+ to zero braking routines, and it always removed the vibrations. Do it 6 to 10 times and it should correct your problem. I have never had to do it again since I changed pads.
 
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