Last post on Sep 03, 2013 at 5:22 PM
You are in the Toyota Prius
What is this discussion about?
Toyota Prius, Brakes, Hatchback, Sedan
Go to NHTSA to file a safety complaint.
Or call Monday-Friday (8 am to 8 pm ET) (888) 327-4236 TTY: (800)424-9153
#211 of 370 NHW11 vs NHW20 vs ZVW30 brakes
Mar 01, 2010 (4:23 pm)
The ZVW30 Prius, 2010-current, has the redesigned brake system and the recent recall to get rid of a rare, brake pause. The NHW20, 2004-09, has not been recalled but there are reports that it has a similar but less severe pause. The NHW11, 2001-03, is my commuting car and none of my tests have replicated the brake pause.
2010-current Prius - SSC-A0B
You don't have to wait on a letter or call from the dealer. Call your local Toyota Service Center and schedule an appointment. If the service writer gives you any grief, ask to speak to their manager ... keep going until you get the right answer, "Yes, come in and we'll fix it." Alternatively, call another Toyota dealer or ask them if you should call the local newspaper.
The problem is rare and intermittent. Probably the surprise, more than anything else, catches folks off guard. Just press harder on the brake and the car stops almost instantly. In the meanwhile, keep your following distance on the long.
There are reports but sad to say, I'm not having much luck documenting the pause. I have an accelerometer that clearly showed the ZVW30 brake pause but I've yet to find someone with a NHW20 to test. I may have to rent one.
We have a poll going on in PriusChat about the brakes and the numbers are:
55 - Yes, I want it fixed (22%)
41 - Yes, However it doesn't bother me (16%)
153 - No, I don't feel my GEN II Prius has a problem (61%)
So over half don't see a problem. Only 22%, 1 in 4, wants a fix.
I have one and following the same protocol as our ZVW30, I can't find any pause in the braking using the accelerometer.
#212 of 370 Re: NHW11 vs NHW20 vs ZVW30 brakes [bwilson4web]
Mar 02, 2010 (12:42 pm)
Perhaps you could post your general area and someone that lives near you could volunteer.
I have a 08 Prius and I have experienced the the momentary release of the brakes when hitting a pothole or rough road, but immediately after the brakes grab. I have even hit areas of ice and the ABS has always kicked and assisted in a timely stop. So over all I am more than happy with the performance of the braking system. Although I wouldn't complain if they removed or shortened the momentary release when you hit a pothole.
#213 of 370 Re: NHW11 vs NHW20 vs ZVW30 brakes [sthoge]
Mar 02, 2010 (1:39 pm)
I'm not saying you are not being truthful - however, I am saying you must have not take all situations into consideration. If you were behind someone at a safe distance and they slammed on the brakes for whatever reason. Then, you attempt an emergency stop and a bump in the road causes a couple seconds of complete loss of braking... almost guaranteed an accident will occur. The next step (after making sure that everyone is ok) is deciding who's then who is at fault?
I stand by my prior accusations that the poor engineering of the car is the reason for the accident. Thus, Toyota is at fault for not addressing the problem in the 2nd & 3rd generation Prius.
#214 of 370 Re: NHW11 vs NHW20 vs ZVW30 brakes [sthoge]
Mar 02, 2010 (8:42 pm)
"Perhaps you could post your general area and someone that lives near you could volunteer."
I'm in Huntsville AL and had one possible volunteer but he never followed up. So I'm thinking rental car. But I'll need a rainy day for the test.
The other option is the iPhone and iPod Touch have a built-in accelerator chip. I have no fiscal interest in them but there are at least two applications that record accelerations fast enough to gather engineering data over short intervals. Dynolicious Logger is one I've tested and within short intervals, 30-45 seconds, the data is usable. Unfortunately, I'm see long term drift that limits it to mostly short tests like the brake pause.
#215 of 370 Prius 2010 Brake fix
Mar 04, 2010 (3:51 pm)
Well it happened again yesterday. Fourth time on my new (January '10) Prius.
I was slowing for a turn, going about 18mph and the car surged ahead.
I thought there was a recall but I still haven't heard anything from them yet.
Does anyone know if the "flash" worked?
Mar 04, 2010 (5:39 pm)
If your car was made in the last week of January, it already has the post-recall brake configuration; your dealer will know. Mine, bought Decemer 12 needed the fix and I got it February 15 in a one-hour visit to the dealer. I still have not received paperwork from Toyota Motor Sales USA about the recall, but I did get an email about it from the dealer about a month ago and I immediately made an appointment. The problem it fixes, disconnection of the ABS momentarily when you hit a bump or one or both traction wheels lose road contact, is something I experienced early and got used to. I did not really need the recall because I knew my brake was always operative and I use it automatically in those situations, with no need for ABS support. A couple of times the ABS activated on snow, and I did not like it all, and it did not help (I did not expect it to).
On the "other" brake issue, my dealer told me in a phone call yesterday that all Toyota hybrids " already have brake override." I think that is not the correct use of the term, because what the service department told me was that the brake pedal always "has precedence" if both accelerator and brake are pushed simultaneously. I think true brake override would mean the engine shifts to neutral when both pedals are pushed, with no need to touch the shift. The dealer is mailing me a 16-page hardcopy explanation of how the Prius brakes work; she said it was technical, but I am very interested in reading it. As far as I know, it is not available on the Web, but your dealer might have it.
#217 of 370 Re: NHW11 vs NHW20 vs ZVW30 brakes [bwilson4web]
Mar 04, 2010 (5:53 pm)
Your engineering and Prius knowledge is breathtaking. I am no engineer, but I have learned a lot from your posts. Thanks for locking onto this set of issues and letting us learn what you are finding and what the loose ends are. You are helping me retain confidence in my 2010, the quirks of which I have mostly found--I think--and adjusted to. I remain impressed with the car and hope Toyota can manage its way through the current mess with honesty and sincerity. There is a lot of bad information and also disinformation (I sense) floating around.
#218 of 370 class action suit?
Mar 04, 2010 (7:05 pm)
I had posted a while back about my accident in Dec 2009 that I had with my 2009 Prius, where my brakes failed at a low speed and rear-ended the car in front of me. I've been seeing lately a lot of people noting that 2nd gens have been also experiencing the problems and are upset that Toyota hasn't done anything to find a solution. I am one that is very upset as well. I have brought the car in to be inspected and called Toyota multiple times about my brakes before and AFTER the accident and they keep telling me "there's nothing wrong w/ them" despite almost everyday occurences of going over potholes and feeling that temporary loss of sensation from braking. My favorite was when they were trying to argue with me on the phone what happened- "your car must have slid on something, like ice." <---- Really? I did a walk around my car after the accident.. there was no ice/ no snow/zilch. Your car has a defect!! Oh and my other favorite Toyota rep. telling me to just trade the car in if that's how I felt. Overall, I'm frustrated and don't know what's the next step about this car and how to deal with Toyota... So here's my question: Any one aware of any civil action suits involving the 2nd generation brakes? Because I would love to know so I can hop on board and have Toyota solve the problem for the whole Prius line and feel safe driving it again. I've absolutely had it with Toyota right now.
#219 of 370 Re: Prius 2010 Brake fix [whitecliff]
Mar 05, 2010 (6:59 am)
So why are you still driving it?
#220 of 370 Re: Prius 2010 Brake fix [whitecliff]
Mar 05, 2010 (8:44 am)
"..I was slowing for a turn..." "..car surged forward.."
In the circumstance you describe the VSC may have activated as the result of detecting some minor level of understearing/plowing, or possibly even a bit of over-stearing. If you are already on the brakes then VSC activation will sometimes result in "unbraking"(***) one of both front wheels.
*** Sometimes that might mean an instant disabling of regen braking and the resulting "lurch" forward "seat of the pants" feeling. If the frictional brakes are also already in use then the regen will be disabled along with unbraking of the frictional brakes on one of the front wheels.