2006 Prius shudder when braking

Is this your first prius ? If so, teh regen braking takes a little getting used to. Basically, you dont need to be slamming the brakes with as much force as you may be used to on vehicles with conventional systems.

 

A shudder could also mean that your wheels are not alirgned.

But I do agree that the regen braking felt slightly different then normal braking so it could be related to that.

 

I definately notice this on my husband's Lexus 400h (hybrid) but on my new Prius I can't feel that at all! The Lexus dealer said it was normal - basically the effect of having the braking energy converted to battery power.

 

As long as I break slowly and gradually, I can actually tell when its regenerating, and as I come down to less than 10mph and then to a stop, YES, it gets grabby. My foot's not moving, but the brakes feel like they're doing a grab-release-grab-release. I had to slam the brakes one time just a few days after I got the car (1/6/06), and originally thought it was due to that, but on a return visit to the dealer, I mentioned it, and they threw it up on the rack and checked. He told me all was fine. Yet here I brake, grab-release-grab, and always in the last few seconds, when it switches from regenerative braking to the actual discs I suppose. I'm still playing with it.

 

Yes, we experience the "grabby" feeling in our 2006 at very low speeds.

You almost always get one "grab" when transitioning from regen to friction brakes at around 7 or 6 miles per hour.

But we have also noticed that if you are creeping along in slow traffic by slightly lifting your foot from the brake (as you might with any car with an automatic transmission), we can get a repetitive creep-grab-creep-grab feeling at about 3mph.

I don't remember this from our 1000+mi test drive of a 2005 Prius rental, but then that was mostly highway miles and we may not have noticed every idiosyncrasy.

Another way to tell when you are transitioning from regen to friction, if you tune in your hearing, is to listen for the whine of the inverter.

- Bob R.

 

When I slow down... I usually push the brake very slightly and I can feel a long gradual deceleration which I know is not using the friction brakes at all... but instead is using regenerative braking. Then at 7mph, even though my foot pressure does not change at all... I can feel a slight release, and then a re-application of brakes when the regerneraive brakes dissengage, and the friction brakes kick in.

/Jim

 

I notice something similar. I think it's due to the gas engine shutting off just before coming to a complete stop, and the engine exhibiting a small bit of "run-on" and sputtering as it tries to turn off. Better gas might help; you could try midgrade or premium to see if it reduces. I've thought about doing this but it doesn't bother me enough yet.

Kirk
San Jose

 

Could be that too.. and as stated.... the friction doesn't kick in till under about 7 or 8 mph unless you really romp on the brake.

 

I too have the shuddering thing, very soft but noticible. At least for my car, I know it has nothing to do with the ICE because it happens in stealth mode too - which I'm starting to master with only 250 miles so far

I had originally thought that I just needed to wear in the break pads, which dont seem to get enough use to break in - but it's sounding like that's not the case. I'm half tempted to kind find my favourite giant downhill and ride the brakes in neutral....

Anyone with a 2006 NOT notice this? Or notice it and have it go away?

Dave

 

I don't notice it.. mine is very smooth.

 

I've had my 2006 Barcelona Red for 1 week as of today. I had seen similar posts and was wondering how the braking would feel. My braking is very smooth and almost identical to previous "non-hybrid" cars I have owned. I do notice sometimes that if I coast up to a stop from quite a distance, this allows for regen and then just as I stop I feel the ICE stutter a little as it is shutting down. But his is not at every stop as sometimes the ICE has already shut down, or still needs to run. The point is, I don't feel anything unusual with the brakes. The car handles great!

 

kirk,

the prius is not made to run on higher octane gas. this can cause starting problems. higher cost/higher octane does not by default mean "better."

-g

 

I too sometimes have 2-4 shudders while I'm braking once I get below 10 mph (maybe below 5 mph) w/steady pressure on the brake pedal on my 06. From the MFD, it looks like ICE is off at the time and I've either got the blue arrow going to the battery or yellow arrows coming out of the battery to the electric motor.


It almost resembles ABS kicking in but I'm not braking hard and pavement isn't loose or wet. I'm just coming from a crawl to a stop.

I'm not sure if it's normal since I've only test driven an 04 Prius >1 year ago and never noticed this.

 

That prob not the friction braking "that occurs below about 7 or 8 mph, and its possibly not dieseling either... I have the 06... the thing I sometimes feel is still so smooth that I assume its just the engine shutting off and the car is going so slow and quiet by then that its noticable, but it could be some mild dieseling.. I'm not sure.

If so.. I hear that goes away as the car breaks in and also when the weather is warmer.

 

I have an '06 and have not noticed this at all. But I will pay closer attention and report back if I do. I drove an '05 shortly after getting my new '06 and noticed that the brakes on the '05 felt much more grabby right at the end of the stop. Perhaps this is the transition from regen to regular braking that somebody mentioned. But I have not noticed what I would call "shuddering" in either model year.

 

I agree.. other than hearing the engine turn off occasionally "usually happens after its already stopped anyway" the stopping is very smooth... I have tried to feel when the friction brakes kick in, but i can't feel when it happens.

Slightly off topic about smoothness:
I also love how smooth the ICE is when stopped.... it runs perfect!...no misses or variances.
When accelerating.. its really cool to not hear a shift but the pitch stays the same.

 

One thing to consider is that the ICE needs to be (and is) controlled to a specific stop position as it shuts down.

This specific stop position is necessary in order to attain a smooth subsequent startup of the ICE.

Needless to say, the act of positioning the engine can result in a small reaction force from the transaxle. It is possible that a sensitive driver, or one who is looking for it, may be able to perceive this.

Please note, having read this thread, there will likely be more people "looking" for this characteristic.

One certainty is that no dieseling is occuring, as the computer controls the fuel via the injectors at the time of engine shutdown.