Brakes Stutter right before the car stops.

I agree with hobbit. This is an idiosyncrasy of the Prii's computer controlled brakes and electric propulsion systems. I also feel this happen fairly often, but I have yet to read where even one person has said this phenomenon has caused the them to lose control of their car . . . so let's not get all bent out of shape thinking there is a serious problem with our Prii. This is not something new to the 2006s!

To me it feels like the brake actuator chattering open and closed in rapid succession. I believe this is induced by the tendency of drivers to ease up on the brake pedal during the last foot or two prior to coming to a complete stop . . . in an effort to prevent the car from doing the “I'm a new driver, watch me come to a jerky, whiplash inducing, stop.†With such light pressure on the brake pedal, the computers may be confused and not know if you are trying to stop or go. The car may be rapidly switching between braking and applying power to the motor for creep. Since the Prii's mechanical brakes are used less than your average car, the brake rotors have a tendency to stay wet or moist longer. This may help amplify the grab/release sensation.

For those of you still new to the nuances of Prius driving, when fully stopped, if you don't apply enough pressure on the brake pedal, the computer will apply power to the electric motor, but still keep the brakes applied. This is to help stop the Prius from rolling backward when stopped on an uphill incline. (While fully stopped, watch the Energy Monitor on the MFD and very slowly let off of the brake pedal. You will see power being applied to the wheels, yet the brakes are still applied and you aren't moving.) If you don't apply enough pedal pressure during the last foot or so while stopping, you may be causing the same thing to happen . . . . stop and go at the same time - except this time you are still slightly moving and can feel the grab/release.

Relax. This ain't gonna kill you.

 

Brake grabbing in the Prius feels to me like any car with drum brakes.

 

Reply to LowSpeed.

I did a few neutral brakes on my way home last night and it definitely made a diff.
This morning, it was back to it's usual "bucking". Then as I was coming to a stop on an up hill slant, it was perfectly smooth with no let off. Coming down the other side of the hill, as I came to a stop, I was using a LOT more pressure on the brakes to overcome the gravity of the hill. The car shook pretty good on that one.

I think the thing's just too damn sensitive coupled with sticky rotors and pads from not being used much. I've enjoyed this thread and can relate to your frustration. :huh:

 

Well, call it a problem or call it a characteristic or an idiosyncracy - the differentiation is pedantic, the symtoms are real.
I find it to be the most annoying issue with the car. (Yes, I do love the car. ) Ive experimented with bedding the brakes and with different modulation techniques and I'm still not satisfied. I'd much rather see a TSB make it all go away - and calling it a "characteristic" is going to get us nowhere.

Dave

 

What happened? The "simple solution" you were all cocky about didn't work? :huh:
The front brake rotors will rust up again, and they will get wet and stay moist again, and IT will happen again. But I guess that is just a bunch of “hybrid crap bla bla...†to you.

Be careful of what you ask for. Toyota could “fix†the problem by dumbing-down our brakes to be more like the first generation Priis'. I don't think any of them have complained about their brakes . . . but that is not a "characteristic" I would be thrilled with.

 

My '06 Prius also does this. I don't notice much, if any jerking, but it makes an "erk, erk, erk" sound just as I come to a smooth stop. She has done it since new and she now has 2700 miles.

This isn't related to rotor cleanliness, a heavy foot, or break-in period. It happens, as others have said, when I ease up off of the brake just as I come to a smooth stop (in order to avoid that last second jerk). It's a minor annoyance in an otherwise absolutlely wonderful car.

"06 Silver Pine Pkg. 7

 

Come on Patrick - you don't honestly believe that a TSB would throw the baby out with the bathwater, do you? What's so "amazing" or wrong about acknowledging a problem and wishing it were fixed? On my '06 it's bad enough that passengers have asked "what's wrong with the car?" when it does the rare left right shimmy at 2mph that others here have noticed too.... Given the 2004's don't seem to have it, I find it hard to imagine a fix setting the car backwards. Maybe the problem just isn't affecting your vehicle or annoying you as much?

Cheers!
Dave

 

When someone is concerned, frustrated, and seeking help and advice, then you give him a response like this, what do you expect? C'mon!

"Belittle" would be positive criticism in this instance as far as I'm concerned. Some people are down right rude in the fact that they don't fully understand the post and put a reply in that's 100% off topic. They therefore, open themselves up to belittling. IMO.

Now with that being said. No more posts here as it is again totally off topic.

THREAD CLOSED!

 

I too had this stutttering of brakes. Talked to the dealer to get the answer its normal. Couldnt expect more from him though. Btw; mine is a 06, 6 monts and 10,000 miles. I have driven my cousins 05, 15,000 miles and it brakes damn smooth. Apparently i am experiencing this grab-release problem or 'charachteristic' as some may say, since last 2000 miles ....it wasnt that prominent before. Having read so many posts ...never thought anyone offered any solution or conclusion. Hey is toyota customer service is the answer? anyone tried that?

 

<div class='quotetop'>QUOTE(unruhly @ Mar 9 2006, 10:06 AM) [snapback]222684[/snapback]</div>

Not that it matters in the least, but I want to join the class action here.. My '06 does it too.

 

I see this thread is waking up again. I'm not surprised now that the weather is changing.

Well, here's my update.

I've got 15,000 miles on the car now. That should be more than enough break in period don't you think?

The bucking at stops continues although through the summer it was far less noticeable. Now that the weather is cooling off and there is considerable dew in the morning, I believe it is coming back to the point I consider it quite annoying. I've actually come to know when to expect it and change my braking to limit it's affect. I shouldn't have to do that.



I'm taking the car in for the 15k service and will let you know what they say.

 

<div class='quotetop'>QUOTE(unruhly @ Nov 1 2006, 11:20 AM) [snapback]341916[/snapback]</div>

Unruhly, I was one of the people in the original "Brakes grabbing" thread and I to this day am having the same exact problem you have described thoroughly in all your posts within this particular thread.

Your post quoted above coincides completely with my current braking characteristics as well. Coincidently my 15K service will be coming up in a couple of months as well, and I had planned on bringing that up. The last two times I had been unable to duplicate the problem at the dealership, but it has become far more consistent now and I doubt I won't be able to this time.

When you take your Prius in for your 15K service and if you are able to duplicate the problem, could you please let me know the detailed analysis and findings? Perhaps I could use that info on my end when I take my Prius in.

If these threads are too convoluted or closed by then, you can just PM me the info. I would really appreciate it. Thanks.

 

<div class='quotetop'>QUOTE(lowspeed @ Mar 6 2006, 11:40 AM) [snapback]221106[/snapback]</div>

Are you sure the stutter might not be the gas motor shutting down. i get a stutter when I am almost stopped and the gas motor shuts down. Thought this was normal?