Brakes Stutter right before the car stops.

[lowspeed]

Our new 06 prius sometimes doesn't stop smooth when it reaches the 2->0 Miles an hour. I thought that maybe the brakes need to brake in ... but we now passed 1000 miles.


What could cause this ? should i take it to the dealer ? or time will fix it ?


** Attention **

I really think this happens in a very limited amount of cars. maybe less than 1%, and i think only 06's

I want to start a VIN# collection. Maybe we can find a pattern.

Please send at least your VIN # and name to priusbrakes@gmail.com, you may also include a phone number, but that's optional.

If we get enough people participating i will be able to at least contact Toyota's president office to get this escalated.
Thanks!
P.S only cars that have the "before stop stutter"... AND PLEASE read the entire thread to make sure your problem matches these symptoms.

[jared2]

Originally posted by lowspeed@Mar 6 2006, 01:40 PM
Our new 06 prius sometimes doesnt stop smooth when it reaches the 2->0 Miles an hour.  I thought that maybe the breaks need to break in ... but we now passed 1000 miles.
What could cause this ?  should i take it to the dealer ?  or time will fix it  ?

[snapback]221106[/snapback]

Maybe the breaks need to brake in. Ask the dealer to give you a brake. Or a break as the case may be.

[modernsituations]

Yeah i get that same thing...i'm at 700 miles. It does it just how you describe. Anyone else have a similar issue that was resloved or know if this is normal?

[aaf709]

What is it exactly? Is it a shudder? Is there a sound like a squeal? When it happens, is it always when the engine is warm or cold (or at both times)?

[modernsituations]

It's kind of like something is gripped and then released with a low grunt everytime you step on the breaks coming to a stop. I thought it was a cold engine thing, but i've noticed it happens both times. It's pretty strange...and i don't like it...

[unruhly]

Mine does this as well. Not too sure why, but I know it's normal 'cause I test drove three different cars. Heres my take.

As you slow down, the majority (if not all) of the braking is being done by the motor. As you reach about 8 MPH the amount of drag from generating power falls off, so the computer has to estimate how much pressure to apply to the brakes to finish stopping the car.
Almost simultaneously, as the brakes are being applied by the computer, you are letting up on the brake pedal for a smoother stop. This end up letting too much pressure off of the brakes as the computer will try to stop smoothly by itself.

I have tried steady pressure on the brake pedal, and it does stop much smoother, but gives a jerk at the very end. I've noticed too that the "let off" feels like it happens on the left wheel, then the right wheel causing a sort of rocking motion.

It sure would be nice to have a theory of operation manual. Does anyone know if one exists?

[lowspeed]

Originally posted by modernsituations@Mar 6 2006, 12:58 PM
It's kind of like something is gripped and then released with a low grunt everytime you step on the breaks coming to a stop. I thought it was a cold engine thing, but i've noticed it happens both times. It's pretty strange...and i don't like it...

[snapback]221123[/snapback]

Exactly... i didn't have that on my 2004 prius.

[lowspeed]

Originally posted by unruhly@Mar 6 2006, 12:58 PM
Mine does this as well.  Not too sure why, but I know it's normal 'cause I test drove three different cars.  Heres my take.

As you slow down, the majority (if not all) of the braking is being done by the motor.  As you reach about 8 MPH the amount of drag from generating power falls off, so the computer has to estimate how much pressure to apply to the brakes to finish stopping the car. 
Almost simultaneously, as the brakes are being applied by the computer, you are letting up on the brake pedal for a smoother stop.  This end up letting too much pressure off of the brakes as the computer will try to stop smoothly by itself.

I have tried steady pressure on the brake pedal, and it does stop much smoother, but gives a jerk at the very end.  I've noticed too that the "let off" feels like it happens on the left wheel, then the right wheel causing a sort of rocking motion.

It sure would be nice to have a theory of operation manual. Does anyone know if one exists?

[snapback]221124[/snapback]

It's not normal... it happens way after the mechanical breaks are already in use.

Right before the car stops.

[aaf709]

Originally posted by unruhly@Mar 6 2006, 09:58 AM
It sure would be nice to have a theory of operation manual. Does anyone know if one exists?

[snapback]221124[/snapback]

Well, there's the 5 Stages of Hybrid Operation. I was trying to see if it was the shudder that happens sometimes when stopping.

[Airgetlam]

I'd hazard a guess that there may be an issue with the anti-lock brake sensor.

Not happening on my 2005, for sure. Although I do get annoyed when accelerating from a stop over gravel and the car decides I'm on ice and reduces engine power.....