pixmation

Just wondering, was thinking about trying some panic stop but haven't gotten around to try yet.

When the brake assist engages, does the brake pedal stay down for a little longer?

Rick

The pedal pulls down and away from your foot, which is a little un-nerving the first time you feel it. The first time I needed it, by reaction, I pressed down harder. ABS took over from there and the pedal pulsed under my foot. The good news is....the brakes didn't lock and I didn't wrinkle my baby....

jpgroom

I don't think it requires a panic stop. I think I can feel a more than linear reaction when stopping. Next time I can steal the car from the wife I will try a panic stop on a smooth road to see what happens. By the way, on an Air Force E-4B (Boeing 747) test flight, the pilot engaged the brake assist on a high speed taxi. It was a toggle switch if I can remember and stopped the 700,000 lb plane pretty quick. That was 16 years ago and I can't believe it has taken this long to get on autos

MarkL

I have not experimented w/ the brake assist, but according to the literature, it does only occur in a "panic" situation. There's a sensor which detects the speed & pressure you're applying to the brake pedal. If this exceeds some thresshold, brake assist "takes over". When you let up on the pedal, whether the car has stopped completetly or not, brake assist disengages.

Bud

I have experienced it with my ML. I was only going about 50, cars in front of me were stopping, so I pressed the brake pedal, but certainly not to the floor and all of a sudden my ML just slowed down incredibly fast, I wondered what happened because I wasn't braking that hard. I realized the brake assist had taken over. It's hard to describe the feeling. The only way to know it had happened was how fast it braked. I think it's fantastic. I think it will do as it is suppsed to, i.e., when it thinks you're doing hard braking but not flooring the pedal it presses the brakes harder for you.

Rick

Brake assist activates based on the time interval between lifting off the the gas and touching the brake pedal.

Maverick666

Does my car has this???

Lynn

Yes.

MarkL

Rick, I'm not sure about this. I believe it only senses the brake pedal pressure/speed of depression. I mean, you could be coasting at 50mph (lifted off accelerator), then need to stop very quickly. I don't think it depends on when you lifted the accelerator.

BigBadDad

I guess I am a fast brake pedal pusher. When I first got my C, I was activating brake assist while stopping at stoplights. It does catch you by surprise. My main concern was someone rearending me, it stops you FAST! My braking technique has adjusted and brake assist hasn't reared its ugly head in quite some time.

pokerFACE

I hear you. With my former 95 3 series I used to tap my brakes very often to make "minute adjustments" haha.. dont ask..

anyway, first time I triggered BAS on the C240 all my books got shoved from the passenger seat into the glove compartment. I totally wasnt expecting it. just some lady pulled in front of me and I needed to slow down, but in no way did I want to stop.

MarkL

You don't have to come to a stop w/ BAS engaged, simply release the brake pedal and it will disengage -- you'll continue moving.

renncpe

I have had it activate once while driving. I can’t reproduce it just by hitting the brakes. I was cut off by another driver. I think that it reads your retina and knows you are really panicked. Any way it worked like nothing I had experienced before. It was really violent. It threw my wife on to the floor and under the dash. She should have had on the seat belt. It was kind of funny afterwards. But it did prevent me from running into that guy.

Randy

BrabusCClass

It caught me by surprise and scared me. Lol. It is very crazy and stops you so fast its unbelievable. Some one cut me off and I started to push down the petal, except all of the sudden it went in by itself and flung my body forward grabbing really hard on the brakes. I didnt know about brake assist so you can imagine my surprise. Its nice to know its there for emergencies.

MarkL

I thought my sister was the only person not wearing a belt ALL THE TIME!! It's for her own good -- get her to belt up! (Forgive my admonition, but you can't control when you'll need it ).

I used to wear my seat belt "sometimes" until I had a near miss on the beltway in Virginia in 1982. I was nearly side-swiped by a female who just got her license and was rushing to the airport. I saw her out of the corner of my eye and swerved only to begin fishtailing (no ESP back then.) I did a 180 and ended up next to the guard rail with lots of headlights coming toward me. Luckily neither me or my car were hurt. Since that day, I've never driven without my seat belt snugly fastened.

pel C

I'm with BigBadDad - experiment, then adjust accordingly. While cruising through a tiny town, looking everywhere but forward, a pickup pulled out in front - I swerved, had no intention of stopping, but the car determined otherwise. And you do stop quickly! Don't care to repeat that experience, although it's nice to know it's there if you really need it.

pokerFACE

MarkL: Yes, I know full well how the systems in my car works (well, in theory ) but just that time when I first got the C240, I didn't realize how effective it worked, and before I knew what was going on, I was stopped.

MB-BOB

This subject reminds me of a tragic story...

I used to work the news desk at a TV station. Got called out one night to the scene of a fatal one-car accident. A woman had plowed her mid-70's land barge headlong into a very stout tree. The Police figured the impact did NOT kill her. However, the umbrella she kept stored on the package shelf above the rear seat DID decapitate her. Not a pretty sight...

Somehow, Brake Assist reminds me of this event. The rear seat headrests on our Sedans and Coupes would hamper the forward motion of large items on the package shelf (or Coupe hatch cover), but I imagine the violent nature of Brake Assist engagement would launch anything else forward with great force.

Hoping you guys don't store anything in these areas... It's not worth the chance.

Flashman

The G-Forces of rapid braking are not that high, I'm guessing under 3. Not enough to launch something hard enough to decapitate you (well, except for that machete you keep in the back of your car)...

It's the G-Forces of a sudden stop/crash that will launch items with such force. Now we are talking G-Forces in the 10-30-60 range... or worst...

MarkL

Sorry, I guess I shouldn't give advice when I haven't gone through the drill myself . Some people might not be as well informed as you are. . Remember, one guy asked if his car even had this...

pixmation

with the coupe's hatch back, luckily can't really put anything on the cover.
Even when I had my old sedan, I only had a box of kleenx there.

pokerFACE

MarkL: "well informed" haha

tommy

that MB-BOB tries to sneak in the fact that he was on tv as much as possible?

Reminds me of "One time at bandcamp..." from American Pie.

elchinocache

i have felt the brake assist kick in a bunch of times. Usually when i brake lightly for a long time after a few seconds the brake assist will kick in and slow the car down faster than i want it to. I like to give myself time to brake, and come to think of it it usually kicks in when i'm going down a hill. it feels funnny because the brake pedal will all of the sudden get really soft and move forward.

r_liebo

Had the exact same problem. Found it very hard to modulate the brakes initially, until I adjusted to the brake assist. My wife was about to kill me with all the unintended panic stops I was making. Now no problems with it at all.