loss of braking while going over bumps???

Known issue with the regen braking switching over to physical braking.

Many other post on this. Try the search.

I can not post links yet as I am still a noob.

 

I have an '06 and when I drive from NH to VT in Bellows Falls I cross a bridge with an expansion joint near a stop sign, it's a slight uphill so I'm usually not de-accelerating and I always lose my brakes(after going over the expansion joint) as I start to stop, it's something that just happens, but... it' get's interesting winters when there's snow and ice on the road, losing traction for that 1/2 second may make a difference at some point, sliding out into an intersection would be the result. True it happens at 5mph and below but sliding on ice with no brakes makes for apprehension, IMHO

 

here is some info from Gen3 forums:
http://priuschat.com/forums/gen-iii...9743-brakes-dont-stop-well-in-some-areas.html
http://priuschat.com/forums/gen-iii...o-brake-surge-still-there-despite-recall.html

basically it is a "feature" you have to be aware of.

 

There was a recall in 2010 where they updated the software to reduce the transition time when transitioning from regen to friction braking in the case of loss of traction. The 2011 already has this "fix".

You just need to be aware of this issue and allow a little more braking room when light braking over rough or slick surfaces. If my wife was driving around with my newborn I would hope that she was leaving a little extra room in front of her and not following too closely.

If this still bothers you, maybe you seriously need to look at a different car.

 

I also had my Prius for while (about a year) before I noticed this issue. When I'd read people complaining about it I'd often think that they were exaggerating because I hadn't noticed it so bad myself.

Lately I've been driving on some rougher roads that trigger it, and yeah it can be pretty disconcerting at first. It really feels like your brakes have just suddenly released doesn't it. After some consideration however I think it's more about the "feeling" rather than any really significant increase in stopping distance. It's like that awful feeling that you've just lost your brakes, but I'm sort of used to it now that I know it's only brief and that firmer pedal pressure will overcome it anyway.

Take your wife over some roads that trigger it and ask her how she feels about it. My wife has never mentioned it to me so I assumed she'd never experienced it, however it turned out (just asked her now) that she had, but it hadn't bothered her too much. I guess she leaves even more stopping distance than me.

 

p123456789: Please update your user info w/your year of Prius. At first I was confused since some folks have cited 3rd gen (2010+) threads and mentioned the recall on the 2010.

I have an 06 and I'm used the behavior. It's no big deal to me. You can see how I voted at http://priuschat.com/forums/gen-iii...99-poll-prius-brakes-problem.html#post1031776. Please also see Doug's post at http://priuschat.com/forums/prius-h...ius-brake-recall-little-more-information.html, specifically regarding the 2nd gen, which the 06 is.

 

Human perception sucks. It is not a problem and only lasts for a few hundred milliseconds. And you still decelerate, just not as fast. There is no increase in speed or lack of braking. It just decelerates less. What you feel is the jerk, or change in acceleration.

Humans pick that up well. What humans don't do is note the magnitude of the jerk well. Get an accelerometer and you will see it is not a big deal. You need to retrain your senses now that you know what you are looking for. In no way is it unsafe. If you are panic stopping, you are using friction brakes anyways, no issue.

 

it becomes more noticeable when tires wear out and grip less.

yes it is not as bad as long as you don't have a habit of stopping 1' away from car in front.

 

For the OP:

2k1Toaster has the correct response. The sensation you describe is an artifact of ABS braking. Regenerative braking means that you are more likely to end up in ABS mode. It's not a safety issue: keep braking and everything works just as it should.

As a minor rebuke: this topic has been addressed hundreds of times on this site. A quick search would have saved time for everyone.

Tom

 

Yep. I'd already read about it so many times before it happened to me, that when it did I knew exactly what was going on and wasn't alarmed.

 

I just got out of an '09 Jetta TDI, you don't want to go there. I've gone through the braking thing with the Prius a couple of times and I didn't think it was a big deal. If you keep the pressure on the brake pedal, the car sorts itself out and settles down.

 

Physics trumps perception.

Before you make a malformed sub-optimal decision, go rent an accelerometer if you do not believe the multiple scientists and engineers that have quantified the sensation you "feel" with empirical data that definitively proves it to be a non-issue. It is a physical impossibility for this non-issue to result in any quantifiable reduction in brake capacity.

Or get a bucket of hot water and cold water, blindfold someone and stick their hand in the buckets randomly. They will fail at identifying which is hot and which is cold. Does this prove that liquids that are hot are not hot? No, it proves that humans are terrible sensors.

 

Because body roll is an important factor... You drive on the track routinely? Install a sway bar if it bothers you.

Trouble climbing steep hills? lol. You can't bs me here, I live in the Rocky Mountains ON a mountain. multi-thousand foot elevation drops, 6000ft to 10000ft normal operating conditions up and down and up and down. I-70 has the steepest interstate stretch up the Eisenhower tunnel of anywhere in the country. My little Prius chugs away just fine with traffic up the inclines.

You are just making up excuses. If you don't want it fine, but that is a personal decision based on really poor judgement.

 

hey if you don't like car sell it. Somebody else would be happier with it. It is your loss somebody's find.

With respect to body roll it is an econo-box not a sports car. You can better it by installing anti-roll bar and strut tower brace if you'd like

 

Are you talking about hills in winter, or hills in general? I take my 2006 Prius on rock climbing trips, and I've never had any trouble climbing hills, or mountains for that matter.

Tom

 

I'd just drive slower, but it's your money. Good luck with the PO.., err, I mean, the TDI.