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      03-31-2009, 10:24 AM   #67
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Originally Posted by jm1234 View Post
I've heard this and I have a stupid question about this I'd like to ask. Isn't the hand brake hooked to the rear tires only and isn't there a separate set of parking brake shoes on the car?

http://www.realoem.com/bmw/showparts...85&hg=34&fg=30

I guess I'm wondering if it's possible to warp the front rotors with the parking brake and if even the rear rotors are impacted by them?

Having said that, I never use my hand brake at the track because I'd rather not for no reason than warp my rotors.
You are correct; engaging the parking brake should not technically warp your rotors. It should simply melt the parking brake shoes (not the disc brake pads) onto the friction surface, which is obviously also a bad thing.
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      03-31-2009, 10:45 AM   #68
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You are correct; engaging the parking brake should not technically warp your rotors. It should simply melt the parking brake shoes (not the disc brake pads) onto the friction surface, which is obviously also a bad thing.
no, no, no, I was asking if the parking brake is even connected to the front brake system and if not is it possible for it to do anything to the front rotors, pads or anything there?

I was also saying that it sort of looks like the parking brake has it's own set of brake shoes and if these do not press the rear pads against the rear rotor then how does it effect the rear brakes? I'm just looking at the diagram posted so I'm trying to understand how the parking brake works on the M3. I don't see where it connects to the rear calipers, which is what I was expecting to see.
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      03-31-2009, 10:55 AM   #69
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no, no, no, I was asking if the parking brake is even connected to the front brake system and if not is it possible for it to do anything to the front rotors, pads or anything there?
Yes, the parking brake cannot affect the front brakes.

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I was also saying that it sort of looks like the parking brake has it's own set of brake shoes and if these do not press the rear pads against the rear rotor then how does it effect the rear brakes? I'm just looking at the diagram posted so I'm trying to understand how the parking brake works on the M3. I don't see where it connects to the rear calipers, which is what I was expecting to see.
This is what I meant by you are correct. The parking brake has nothing to do with the hydraulic disc brake system. It uses a cable and a separate drum-shoe system that is built into the rear wheel(s). I am not even sure if is just a single wheel or not. In other words, it is a redundant system.

If you get on your brake pedal to stop the car and sit on the brakes after a session (say you decide to chat with someone on your way before parking and apply the brakes for a few minutes while doing so), then I guess you could warp the rotors since you might be affecting how the rotor cools and contracts. That is what I should have said earlier as opposed to referring to the parking brake. It's still not a good idea to engage your parking brake though.
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      03-31-2009, 11:05 AM   #70
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Originally Posted by lucid View Post

If you get on your brake pedal to stop the car and sit on the brakes or something after a session, then I guess you could warp the rotors since you might be affecting how the rotor cools and contracts.

This is why I never use the hand brake after sessions and I confirm it is a drum-based system independant on rear wheel.

I usually leave the car in gear on a flat surface and move it half a wheel after 10-15 minutes to avoid all the heat going only on one side of the discs. Cooling laps are important but not always easy on open sessions with a lot of cars.

Also Lucid, as you mentionned, it is incredible that the BMW technician speaks only about wrapped discs and no word about pad's depot. I am now facing 2 opinions about the same problem and I don't want to have trouble with my dealership.
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      03-31-2009, 11:11 AM   #71
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Yes, the parking brake cannot affect the front brakes.



This is what I meant by you are correct. The parking brake has nothing to do with the hydraulic disc brake system. It uses a cable and a separate drum-shoe like system that is built into the rear wheel(s). I am not even sure if is just a single wheel or not. In other words, it is a redundant system.

If you get on your brake pedal to stop the car and sit on the brakes after a session (say you decide to chat with someone on your way before parking and apply the brakes for a few minutes while doing so), then I guess you could warp the rotors since you might be affecting how the rotor cools and contracts. That is what I should have said earlier as opposed to referring to the parking brake. It's still not a good idea to engage your parking brake though.
My bad, sorry. I see that you were (very clearly) talking about the parking brake pads and not the disk brake pads.

Yes, I see where keeping your foot on the brakes after a session could explain warped or deposit damaged front rotors. If you had to hold the car still on a hill with the engine running after/during a session do you think it would be better to use the parking brake or the disk brakes? I believe the front rotors get hotter than the rears so I think you would be smarter to use the parking brake than the disk brakes. Stupid idea?
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      03-31-2009, 11:17 AM   #72
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If you had to hold the car still on a hill with the engine running after/during a session do you think it would be better to use the parking brake or the disk brakes? I believe the front rotors get hotter than the rears so I think you would be smarter to use the parking brake than the disk brakes. Stupid idea?
Applying the brakes while stopped after a session is a big no-no, so I wouldn't even try it in any manner. I haven't found myself in a situation where I had to do it. The paddocks I've been to are pretty flat. Just identify/claim a flat parking spot for yourself before the session, and make it there after your cooling lap and try to get on the brakes as little as possible, and leave the car in gear as bher has said. I haven't had any problems doing that.
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      03-31-2009, 11:40 AM   #73
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Applying the brakes while stopped after a session is a big no-no, so I wouldn't even try it in any manner. I haven't found myself in a situation where I had to do it. The paddocks I've been to are pretty flat. Just identify/claim a flat parking spot for yourself before the session, and make it there after your cooling lap and try to get on the brakes as little as possible, and leave the car in gear as bher has said. I haven't had any problems doing that.
I was thinking of something weird like a red flag situation or something like that.
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      03-31-2009, 11:49 AM   #74
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I was thinking of something weird like a red flag situation or something like that.
Oh, I see. I haven't been in such a situation, so don't really know. Maybe use the regular brakes and roll the car very slightly every 15 seconds if you can't stop on a flat section?
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      03-31-2009, 11:56 AM   #75
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Hi Guys,

Read all the posts and I am more confused than before.

Facts: 2008, E92M3, 10,000 miles, 50% track use, since last fast tracks, evident vibration on front (left mainly) while breaking, some blue and irregular lines on front discs, bite is normal or better (?): my conclusion was wrapped discs.
1, reading the posts, could it be irregular pads depot on the discs?

2, Was thinking about moving to ap racing, but it seems they are basic products from the very good company. It seems also that 6 pistons is not better than what I have.

3, Is it reasonnable to think that RS19 and brake fluid will be the best $/efficacy move?

Thanks

Mine has only done 3000 miles or so on it, 2 track days, and the front discs are already cooked! They vibrate really badly on high speed and heavy braking - got it swapped out 2 weeks ago from BMW under warranty( the 2 fronts dics were warped). Need to find something more reliable.
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      04-01-2009, 05:41 AM   #76
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Mine has only done 3000 miles or so on it, 2 track days, and the front discs are already cooked! They vibrate really badly on high speed and heavy braking - got it swapped out 2 weeks ago from BMW under warranty( the 2 fronts dics were warped). Need to find something more reliable.

Dealer and a friend mecanician confirmed wrapped discs. I am currently thinking about AP racing 6 pistons, price for the all kit (caliper, pads, fluids, discs) is 2400 + VAT (for 1 pair)
I just register on a french forum to share experience see picture
http://blog.motorsport-passion.com/m...-racing-376mm/

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