Parking Brake With Car in "D"?

[Raikkonen]

Hi Gang,

Hopefully a quick question/answer scenario here:

When I'm at a stoplight, or stopped anywhere for that matter, to avoid rolling while in Drive (as opposed to just pressing the brake pedal), can I use the parking brake without causing any damage to the DCT transmission?

Assuming it's not in "creep" mode, I can't imagine this would do any damage, as there aren't any clutches engaged. I'm assuming this would be the same as me just keeping my foot on the brake pedal...Thoughts?

Thanks!

[GregW / Oregon]

Originally Posted by Raikkonen

Hi Gang,

Hopefully a quick question/answer scenario here:

When I'm at a stoplight, or stopped anywhere for that matter, to avoid rolling while in Drive (as opposed to just pressing the brake pedal), can I use the parking brake without causing any damage to the DCT transmission?

Assuming it's not in "creep" mode, I can't imagine this would do any damage, as there aren't any clutches engaged. I'm assuming this would be the same as me just keeping my foot on the brake pedal...Thoughts?

Thanks!

Correct. Only downside I see is you brake lights will not be on so maybe less visible to someone coming up from behind?

[MN2///M]

As electronically aware as these cars are, I would not be certain that the parking brake and foot brake are viewed the same by the computer. If you have a relationship with a BMW technician you can trust, I would ask them.

But if you are taking the time/effort to pull the handbrake, why not just put the car in neutral?

[mkoesel]

Originally Posted by MN2///M

As electronically aware as these cars are, I would not be certain that the parking brake and foot brake are viewed the same by the computer.

As he mentioned, the car is already stopped with the clutches disengaged. So the computer doesn't care at that point whether you engage the parking brake.

[OF Hero]

One benefit of doing this would be to save your rotors from potentially getting warped if you had just done some heavy braking, coming off the freeway, etc, as it would prevent your hot brake pads from being applied to one spot.

[Raikkonen]

Originally Posted by MN2///M

As electronically aware as these cars are, I would not be certain that the parking brake and foot brake are viewed the same by the computer. If you have a relationship with a BMW technician you can trust, I would ask them.

But if you are taking the time/effort to pull the handbrake, why not just put the car in neutral?

Thanks everyone, I appreciate the replies...looks like the consensus would be that I'm "OK" in using the handbrake.

In regards to putting the car in Nuetral, it's a valid question, but as a light turns green, it's one less step for me to simply release the parking brake, as I rest my hand on it to remind me it's engaged.

If I put the car in "N" as well, I would for sure forget to knock it over into Drive, revving like a maniac (loser) when the light turns green!!!

[BavarianDevil]

Originally Posted by OF Hero

One benefit of doing this would be to save your rotors from potentially getting warped if you had just done some heavy braking, coming off the freeway, etc, as it would prevent your hot brake pads from being applied to one spot.

Didn't know this was a problem. Can't imagine applying your brake when stopped is going to warp the rotors regardless of how hot the rotors get.

Hey I know... when you stop just shut the car off. Then it will be in Park. No brakes required. Problem solved. JK.

[DBACE]

I think unless you are in one of the two following scenarios, you are doing it wrong.

"The handbrake turn (also known as the bootlegger's turn) is a driving technique used to deliberately slide a car sideways, either for the purpose of quickly negotiating a very tight bend, or for turning around well within the vehicle's own turning circle."

"In cars, the parking brake, also called hand brake, emergency brake, or e-brake, is a latching brake usually used to keep the vehicle stationary. It is sometimes also used to prevent a vehicle from rolling when the operator needs both feet to operate the clutch and throttle pedals."

If you plan on this being a common thing, you will get distracted and forget it is engaged and cause potential harm to the intended use of the component.

[bd307]

Originally Posted by OF Hero

One benefit of doing this would be to save your rotors from potentially getting warped if you had just done some heavy braking, coming off the freeway, etc, as it would prevent your hot brake pads from being applied to one spot.

Get the facts right before spreading wrong information.

He is not driving on track in this situation he is describing and even he is on track, the rotors do not warp like people are assuming.

[damageprone]

Originally Posted by Raikkonen

Hi Gang,

Assuming it's not in "creep" mode

Thanks!

There's a creep mode?

[mkoesel]

Originally Posted by damageprone

There's a creep mode?

I think its called "Low Speed Assistant" or something like that. Basically, its just the TCU disengaging the clutches when you bring the car to a complete stop, and keeping them that way (so no need to keep your foot on the brake pedal) until you give it throttle input. Then, if you blip the throttle, the car will move forward in first gear (or second gear if you are in D1 or you have manually selected second gear on your own) with the engine at idle speed (just like any car can - whether it has a manual or automatic transmission). Because there is no clutch pedal, this is really the only sensible way for it to behave, so most of us tend not to think about it as a special feature even though BMW seems to characterize it that way.

[CanAutM3]

Originally Posted by BavarianDevil

Didn't know this was a problem. Can't imagine applying your brake when stopped is going to warp the rotors regardless of how hot the rotors get.

It will not warp the rotors. But applying the brakes while they are VERY hot can leave a pad material imprint on the rotor. That imprint can then become the starting point for uneven pad material deposit on the rotor which eventually results in brake shudder. This phenomenon is often misdiagnosed as warped rotors because it exhibits very similar symptoms (all the way to out of spec run-outs on the rotors). But for this to happen, the pads and rotors need to be VERY hot, like right after a track session. Street driving in un-likely to generate enough heat for this to be a concern.

[CPWINCH]

Originally Posted by CanAutM3

It will not warp the rotors. But applying the brakes while they are VERY hot can leave a pad material imprint on the rotor. That imprint can then become the starting point for uneven pad material deposit on the rotor which eventually results in brake shudder. This phenomenon is often misdiagnosed as warped rotors because it exhibits very similar symptoms (all the way to out of spec run-outs on the rotors). But for this to happen, the pads and rotors need to be VERY hot, like right after a track session. Street driving in un-likely to generate enough heat for this to be a concern.

This is true, but applying the parking brake is much worse when getting off the track. That will damage your rotor too. Best practice is when you get off the track just pop the hood and put the car in park and let it cool down (no parking brake)

[Canuckles]

Correct me if I am wrong but doesn't applying the parking brake engage a shoe rather than applying the brake pads?

Of course we are all in agreement with regards to cooling down. But just wanted to clarify.

[bd307]

Originally Posted by Canuckles

Correct me if I am wrong but doesn't applying the parking brake engage a shoe rather than applying the brake pads?

Of course we are all in agreement with regards to cooling down. But just wanted to clarify.

You are right. The shoe of the parking brakes on our cars are independent from the rotors. Does not hurt at all to pull e-brake on our cars after hot sessions. Touching the pads is a different story.

[CanAutM3]

Originally Posted by CPWINCH

This is true, but applying the parking brake is much worse when getting off the track. That will damage your rotor too. Best practice is when you get off the track just pop the hood and put the car in park and let it cool down (no parking brake)

We're going a bit off topic here, but your statement is inaccurate.

On the F8X (as other M3 before it), the parking brake is a separate drum inside the disc hub. It is.perfectly safe to use the handbrake after a track session. I've been doing that over the last 16 years starting with my E46 and never had an issue

[SD ///M4]

I'm not sure why anyone would want to engage the parking brake in active traffic, even if you're stopped at a light. Why isn't just keeping your foot on the brake sufficient? If your foot is on the brake the car won't move, it won't roll.

In a manual transmission car, I come to a stop, pushing in the clutch when necessary. If I'm at a light, I put the transmission in Neutral and then let out the clutch to save wear and tear on the throwout bearing. My foot is on the brake the entire time. When I see that the light is about to turn green, I push in the clutch, put the transmission in 1st, take my foot off the brake, and then move off with traffic.

In my M4 with DCT I just keep my foot on the brake until the light turns green. There is absolutely no reason to engage the parking brake or to even put the transmission in neutral. I have absolutely no idea why you would want to do this.

The only exception to this is if I'm at a train crossing and there's a long train. In that case I will turn off the car and engage the parking brake until the train has passed, then start the car and move off with traffic.

And there's no situation when driving on the street that your brakes are anywhere near hot enough to cause pad transfer.

[GrussGott]

Originally Posted by SD ///M4

I'm not sure why anyone would want to engage the parking brake in active traffic, even if you're stopped at a light.

There is absolutely no reason to engage the parking brake or to even put the transmission in neutral. I have absolutely no idea why you would want to do this.

Easy answer: because I can!

I pull the parking brake all of the time because I only drive the DCT manually (coming from an MT) and have always been in the habit of taking my foot off the brake and pulling the parking (which I keep my hand on). It may not be the best habit, but of all my bad habits, it's the least bad, so it'll be awhile before I get to it.

This fucking bad habit list! so gawd damn long. geezus

[ssuene93]

People just getting lazy. Trying to use the parking brake to hold the car against rolling.

Long time ago when hillside assist is not available on most manual car, I used it to hold the car against it rolling backward before I engage the clutch when I stopped at a very steep stop.

[SD ///M4]

Originally Posted by ssuene93

People just getting lazy. Trying to use the parking brake to hold the car against rolling.

Long time ago when hillside assist is not available on most manual car, I used it to hold the car against it rolling backward before I engage the clutch when I stopped at a very steep stop.

Yes, I have decades of using this technique. But this is only just before engaging the clutch and holding in the button while pulling up on the parking brake.

[ssuene93]

Originally Posted by SD ///M4

Yes, I have decades of using this technique. But this is only just before engaging the clutch and holding in the button while pulling up on the parking brake.

Yes, thats what I mean holding the button and pulling the brake, and release it once clutch is engaged.

[04RC51]

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