Had an at fault accident - braking anomaly - like hit sheet of ice

this thread is confusing between a 25' slide on 'ice' or 'cloud' and a small lurch after hitting a bump while depressing the brake.

 

Can you reproduce it safely, at will or with a high-probability?

The reason I ask is I have an accelerometer that can accurately document the problem I could loan you to document the phenomena:

We used this to generate charts showing the 'brake pause' of the ZVW30:

Later, we confirmed the fix using the same approach.

Understand, my interest is in the engineering analysis. Once we document:

1. How to recreate it
2. Measure the effect

Others who share my curiosity can try to replicate it not only in your model but others. If we can accurately describe the conditions to recreate the problem, we can share this data with responsible parties and an effective repair or 'caution label' developed. Understand this is an intermittent problem and they can be the most difficult diagnose.

Bob Wilson

 

Bob, Ive had this happen to me twice since I bought my Prius 9-14-12. I think you'd be better off finding a Prius owner who has this happen much more regularly. Ive read about the issue after it happened to me and know how to cope with it. Its definitely an eye opener when its happening and Im not sure I'd want to try to recreate it for liability reasons.

 

OP - sorry to hear about your accident. To me this serves as a reminder of just how you always need to be paying attention when driving as things happen so fast. Even with you leaving 70-80 feet this all would have happened in 2 to 3 seconds. I have always heard that the issue with greasy roads is great when it has not rained in a long time. I also live in the Philly area and we have gotten weekly rain for the last 6 to 8 weeks so that at least reduces the chances of this.

If it were me I'd have the dealership look at a few things-

The tires - you said that you thought that you still had a lot of wear left, but I have found that the last few 32's of an inch of tread wear very quickly and you can go from marginal to unacceptable in only a few thousand miles.

The airbags - if you did hit an SUV at 25 mph the airbags really should have deployed. Could this be part of a larger issue?

The ABS system - when a sensor fails the ABS system shuts off completely.

Lastly, you say that even after the car is repaired you do not think that you will feel safe. If this is really the case I'd urge you to give thought to replacing it. Driving a car that you do not feel safe in is not something that is going to be good for you in the long run.

 

Selling a vehicle, to another person, that you are not confident is safe is not really an option either. The thought that someone else could be injured in the same vehicle will haunt you even longer. The problem needs to be determined and fixed, or the vehicle scrapped.

 

Yes I also read about it, and more as I have personally experienced the same: '' brakes would give way for a brief split second''... what I am trying to determine is if the road would have been ''bumpy'' on the distance of i.e. 100meters, - would the brakes be (strange/ or disconnected? or some other abnormal (to me) procedure) few times during the road have been ''bumpy'' or what would be the application in such scenarios?

I have had few of these when my wheel hit the pot hole while braking and my brakes gets shortly (strange/ or disconnected? or some other abnormal (to me) procedure) then again... usually it was one pot hole so I can't at present verify if there is any potential issue on the many many pot holes road or very bumpy road.

Very well, there might be reason for that - I may just don't know ...

 

Ouch ! Hopefully they will make it as good as new & back to normal.

 

Yeah that's a pretty fair ding for 25MPH with 80' stopping distance! That's very surprising.

BTW sas, have you figured out if the wheels lost traction, or slid, or did the brakes just refuse to work at all?

 

Yes, please follow up on the braking issue. I still have a nagging feeling that there might still be something more that we don't yet understand.

 

Reminds me of my College days in Rochester, NY. My Pop asked how I like driving on the snow and ice. In my humorous response I said if you drive 20 MPH and put on the brakes the car speed up to 30 MPH. Best to drive around if you can rather than brake or take the Bus.

 

Just curious sas0611. Any updates?

 

i get this sensation as well sometimes when hitting a pot hole in the road. i know what you are saying and most of the comments here are going after the tires and the road. unless you have had it happen to you it is a odd experience to explain. my 07 with 93k miles has done it since i got it at 85k. the brake pedal holds firm but its like you are just coasting. once the pot hole is clear it brakes fine again. must be a abnormality in the brake actuator or electrical connection somewhere

 

Happens to me all of the time too, if I have to stop for a red light and I see its bumpy, I can feather the brake just right so it doesnt activate ABS and make me coast. But when I first got my Prius I almost rear ended somebody at least 3 times until I got the hang of it....

 

Weird how he never provided an update, even though he posted more in 2013.

 

OP's situation was different than the common pot hole issue.