then I have no idea what your talking about my good man

 

Brake Booster = the part of [just about] any car that uses engine vacuum to boost brake pedal pressure.
Brake Assist = a computer controlled system that will apply full braking force when an emergency situation is detected.

Bosch developed Brake Assist after studies found that over 90% of people fail to apply full braking force during emergency braking. Some systems (mostly on commercial vehicles and some Volvo cars) will even apply the brakes by themselves based on information from a proximity detector.

Scion uses a mechanically-operated Brake Assist system on non-VSC cars and an electronic system on VSC-equipped cars.

 

For more info:

http://en.wikipedia.org/wiki/Brake_assist

 

If you read the manual, that is actually called the Brake Booster for our car ; )

 

DELETE... see next post.

 

Well, I did read the manual... and they don't call it "brake booster." They call it "Brake Assist System" and explain how it works on page 165-166. When they are talking about the "brake booster" on page 164, they mean the vacuum brake booster... like every car with power brakes has. Although I did have a car once that didn't have power brakes... a 1979 Fiat/Bertone X1/9... but that's another story.

Anyway, the point is that Scion/Toyota refers to Brake Assist by its proper name.[/i]

 

anybody feel the xD has quite a bit of brake pedal travel?


just a bit.

 

That's what I thought with mine, and then I got my rear brakes looked and messed with at a nearby shop and boy my brakes are so much better now. When I first got the car it gave me the feeling that I had very little pad left, hence having to push harder+longer, and it got to a point that I'd have to start stopping much sooner than I would normally stop.

I would suggest going to a local shop of yours and having them take a gander at the drums and see what they say.

 

i had much breaking improvement after the rears adjusted after some use. at first it was very scary, but now it's very nice.

 

I tried testing the ABS shortly after I bought the car by slamming the brakes (on dry concrete in an empty road). I didn't feel the ABS engage, but the thing came to such a quick stop that it startled me. Good thing I had my seat belt on :-).

 

So the D is my first car with ABS. I think I have figured out what it is, but it worries me so I'll ask any way. Yes, I read the manual, but it doesn't describe what sounds or really brake pedal behavior will be like.

Sometimes when I go to stop I can't press down on the brake pedal. Well, I can, but it doesn't do me any good. The brakes make this weird noise. It's like a grinding noise or pulling metal wire taught. Since this has only happened since winter appeared I thought maybe I got a piece of rock salt stuck on my rotor, but I've never had this happen with any other car I've driven. So is that the ABS kicking in?

I was pulling to a stop at an intersection and that weird noise started and pressing the brakes was relatively useless. I thought I was going to glide right into the middle of the intersection and into a car, but the car finally stopped. I even pumped the brakes and it didn't help. ABS shouldn't be that scary.

OH, and driving home tonight on roads covered in slush, (what i think is) ABS didn't kick in at all surprisingly. Granted, I drove mostly in second or third gear, but the only time it happened was when I was coming to the end of a stop at a light.

So am I an idiot and this explains ABS or is it something else?

 

I've experienced this in my '05 xB, but on ice, not on snow. The car is good enough that ABS doesn't come into play in slush unless I really slam the brakes, but in snow/ice it's fairly common.

In situations when I have absolutely no traction (and I know it was ice, because the guy in front of my ended up going sideways through the intersection), the brake pedal pushes all the way up. This used to happen on my Blazer: ABS regulates braking by
1) detecting wheel slip, and
2) reducing brake pressure until wheel slip is no longer detected. [This is what replaces pumping the brakes: a turning wheel with traction stops the car faster than a locked wheel.]

The crappier traction is, the more the car has to reduce braking pressure (and the longer it takes you to stop). In my Blazer, when I was mudding or something and skidding around on wet grass or whatever, there are times it would literally shove the pedal back all the way, which in the truck, meant, as you can guess, I had virtually no traction whatsoever.

This was convenient in the Blazer, because it gave me a warning to start looking for somewhere to ditch the car. I'm no mechanic, but I assume it's the same in the xB/xD: you have very, very, very little traction, and assuming you don't immediately rear-end a school bus, you should slow the hell down. Again, this might be a good time to look for some bushes to plow into, instead of the car in front of you.

Oh: and my ABS always, every single time makes a noise like this: "GGGGNGGG NGNGNGNGCCHHH CGC GHGCHCHCHCHKKK GGNGNGNGNGNNNGGNNGGHHH!" If you dropped a cellphone into a garbage disposal, that's the noise I would expect it to make.

When I was in Driver's Ed in the mid-90's, the instructor made a point of saying that it would make a hideous noise and shake like the car is going to explode, because when ABS first came out, people would freak and yank their feet off the pedal.

So it's entirely possible this is perfectly normal. Where is the noise coming from: the foot pedal or the wheels outside the car? I will try to talk my brother into letting me slam on the brakes on his brand-new xD while recording it on my cellphone, but no promises

Hope this helps!

 

spinthetension.

lol that would be abs.
but i wouldn't pump the brakes if i were you, had one of those defensive courses, pumping it just confuses the abs, and instead it wont work =]

 

Yep, that's your ABS doing its work. It may seem like the brakes aren't doing anything when this happens, but that's because you are on a very slippery surface. If you didn't have ABS, your wheels would have locked up and you would have probably slid into the intersection.

 

Just to echo what others are saying, yes that is ABS kicking in. It may seem like "hey my brakes aren't working" but it is just the ABS throttling the brakes. In a non-ABS car the brakes would lock, your wheels would stop, but then you would just be skidding with no control. With ABS, you get all the stopping power possible (given no good traction), but the wheels can still spin enough so you can steer (to avoid obstacles etc).

I feel everyone who is new to an ABS car should find an empty parking lot (a snowy or wet one if available) and slam on their brakes from 20 mph, to experience the brake pedal effects you mention, and to learn how to steer and stop with ABS.

 

Thanks for confirming that it is my ABS. It scared the hell out of me the first few times it happened. I was never taught the 3 S's of ABS, but apparently you are supposed to keep your foot on the brake. Oh well, I'll figure it out. The parking lot at work was a good test run as we had about 2 inches of snow covered in freezing rain which then turned into just rain. Talk about slippery. Once on the roads though everything was fine. No slamming on of brakes 'cause I kinda sorta know how to drive in slippery slush.

Well I'm off to dig my D out of its ice tomb. I try to take pics. =)

 

spin, do you have VSC on your xD? If you do, there'll be a switch in front of the parking brake handle with squiggly lines on it. If you do, a parking lot test will amaze you. Press the button briefly to turn traction control off, press and HOLD the button for 5 seconds to turn VSC off. Get up to about 30 MPH (if it is safe to do so) and see what it takes to make your car spin out of control in a snowy parking lot.

Just a note: Be sure there aren't speed bumps or parking space curbs hidden under the snow!

 

No, sadly I don't have VSC. I got my D about a month before the '09s rolled out. Thr car is handling really well on ice and slush though.

 

haha that's exactly what is sounds like too. thanks!

 

lol... yeah, it should use that description in the manual...