Should Toyota acknowlege that the braking issue applies to the gen II Priuses?

Well,

I do not know about all this.

I just finished driving my new old '04 right through the teeth of this snow that hammered the mid-atlantic. I've been out every day, driving around in horrible conditions.
Yesterday, while approaching an intersection on very smooth packed snow with a nice glaze on
it, I gently applied my brakes, and got nothing resembling any braking effect. I let off the
brakes then braked harder, and the the ABS system started getting to work. Bump-de-bump-bump
and it crawled to a halt.

Now, i too, am an old subie driver. And this behaviour threw me for a loop. I'm quite used to
very gentle braking to avoid lighting the abs, figuring if the abs is activated, I'm probably asking
a bit much of the car. But in the '04, the regen system certainly responds differently to sketcy
road conditions. I won't dare argue that. But brakes 'failed' ?? Nope. They worked.
FWIW, I had, on a few occasions, managed to 'outbrake' the ABS in the outback, I got on'em
hard and fast and managed to lock all 4 before the abs could respond as a deer jumped out on
a curve once. A while later, I tried it again, just to see, and if I just stabbed the brake pedal
as hard as I could, I could lock the wheels. But anything short of a full panic hit to the pedal
would activate the abs. Not sure about the prius, I'm going to go out in a while and try it.

and by the way, the prius responded to this snow very admirably with snows mounted in the front.
I have no complaints concerning this car in the snow. it works just fine. No, it sure ain't a subaru,
but then again, what is?

 

I've had a number of cars with ABS and they have never felt like my 2005 Prius. The occassional loss of braking over a bump actually gives the sensation of a surge forward in the middle of breaking. I half expect it now and so it has helped me rationalize it away as a problem.

I've not seen any numbers on this, but when it has happened to me it has definitely felt like there was a loss of braking (even up to .8 of a second's worth), requiring increased pressure immediately after. It has been particularly apparent when coming up behind someone where there is a real imperative to stop within a set distance (like in bumper to bumper traffic and the car in front stops short).

I can't imagine what a sales-person would have said to a customer experiencing the problem during a test-drive!

We probably have to remember that it is not just our driving we have to be concerned about, but all those others, maybe with less coordination or experience, driving the Prius.

 

But sadly, no one wants to hear from you (or folks that feel the brakes are fine). Sadly, we're not going to be satisfied until your car won't let you get into an accident, or even let a drunk driver enter the car ... it won't let someone do road rage (there will HAVE to be bad emotion sensors) ... so that the public at large is protected ... not even 1 out of 100,000 can fail ... no, there dare not be even 1 out of a million failures, eventually. It reminds me of the social systems we have. We now pay a premium so that everyone who sneaks into the country gets free meds. We all have to pay high taxes for over-crowded prisons. We have to pay & pay & pay. Now, we ignorantly do to auto manufacturing, what we've done to social systems. Eventually we won't be able to afford its complexity. As it is with auto manufacturing, so it goes with society ... it implodes from within, from its own complexity.

 

My 08 has done the weird brake loss/delay thing since the day I got it. I only notice going over one set of train tracks as I come up to that darn red light. I did test drive a 2010 Prius last year but did not drive over that spot to compare.

 

hill must have you on his Ignore list. I haven't seen him belittle your post for being objective.

 

Greetings all! I am a newby with a brake question regarding my 2005 which I bought in Nov 09 with 48K miles. I have noticed that the right rear wheel will hop briefly as I brake the last 3-4 MPH to a stop but only when the roadway is damp or wet. It is exactly like a brake lock up caused by a wet or contaminated brake lining and only the right rear wheel. Anybody have a similar experience? Thanks in advance.

 

Time to file a report with NHTSA?

If so, check the following link: Office of Defects Investigation (ODI), File A Safety Complaint

 

Well after 17,040 miles as of today, I never thought I would post this, but I happened to actually experience the "Problem" today.

I must say some folk are really making much to do about a minor, aprox .7 sec of brake loss due to a rough spot in the road.
I actually started laghing about it... a quick blip, done.
Hell I belch longer than this event lasted!!!
Here is a copy of a post I submitted to bwilson4web for his location database....




Bob, I have one for you... A Gen II report!!

los feliz,ca - Google Maps
Traveling away from camera, rough spot in lower portin of pic, however with recent rains it has degraded further than it looks!

I have a Gen II 08, V and run 42-40 PSI front/rear so I feel a lot of the drive. After 17,000 mies I can tell blindfolded when I am in Regen, Warp Stealth, and Battery or ICE acceleration.
It was medium traffic, coming up to to a stop way ahead, plenty of cars in front of me. I was going 35-40 tops, and since I knew I was going to have to stop ahead, I backed off the gas and went into Warp Stealth for a bit, NO arrows at all,then Regen mode, I traveled like that a bit, then hit brakes lightly. I could feel the deceleration effect, then I hit the rough patch in the pic. I felt the car drop into what felt like Warp Stealth mode, niether acceleration, nor deceleration. The effects lasted pretty much like your accelerometer readings, a split second, right after the bump, the "Problem" occured, a half sec of "Coasting", then deceleration again.
I actually started laughing...
This is what all the fuss is about....
C'mon!!
I promptly went around the block, and repoduced the effect.
Feeling quite pleased with myself for not only noticing the "Effect" but actually reproducing it, I Goggle Mapped the spot for you, and here we are!!!
I will stop by the dealer tomorrow, and talk to my Service Rep, have him put my name on a list of trouble makers. AND MOVE ON!!

Hey, NICE JOB, and ATTABOY, for the accelerometer write up. Well pesented, and honestly as I was laughing, in my head I was flashing back to your graph...Pretty much spot on for the effect I felt!

I downloaded an App for my Droid that will do XYZ readings. I think I will go back and see if I can record the "Effect"
It may not be as sensitive as your unit however!! If it records, I will do a Save Screen and post the pic!!
Thanks for your posts, always a great read!!!

 

I recommend that you have the friction brake on the wheel examined. It is a simple process to remove the tire, then remove the drum, allowing you to inspect the two brake shoes and the drum interior.

Maybe all that is needed is to spray some brake cleaner on the shoes and the drum interior.

Maybe the brake wheel cylinder is starting to leak brake fluid and this is getting on the linings. In that case you'll want to have the wheel cylinder replaced.

Maybe the right rear brake has a tighter adjustment than the left rear brake, so the RR side engages first and is causing the hop.

Or maybe the previous owner had left the parking brake engaged while driving around, which caused unusual wear on the brake shoes and drums, and results in the symptoms you are noticing.

 

Owners could read the manual,learn how to operate the vehicle and know what to expect instead of crying wolf. What a novel concept!!!!

 

Prospective motorcycle operators could read the manual too. It is well settled that a motorcycle is a wee bit more complicated and reading a manual isn't the same thing as a hands-on training program.

Denying the issue will not make it go away. That has already been proven with the current recalls.

 

You are comparing apples to oranges, i love it when people try to do that. The differences between a motorcycle and a car are huge, for example they have two wheels and don't drive or handle even similairly to a four wheeled vehicle, you have to shift with your feet nad the throttle is in your hand ect........AMD THERE ARE MANY OTHER DIFFERENCES!!!! Geezzzzee!

With the hybrid car to std car we are talking about nuances by comparison. Lets get real here! Oh and in my opinion reading the manual would be a huge improvement all you have to do is browse this site and see many many PC members don't and they are enthusiasts, just imagine how bad it is for those that aren't enthusiasts.

 

And that applies to how the limitations (features for the apologists) of the Prius' hybrid safety systems are handled.

If you are unwilling to compel a manufacturer to have their safety systems operate just like a non-hybrid car, then there is an obligation on the manufacturer to clearly explain the differences to the purchaser. Do you think that Toyota did not factor that obligation in to the decision to modify the operation of the brakes on the Gen III Prius? Using your RTFM logic, all Toyota would have had to do to 'solve' the Gen III brake system issues would have been to mail out a revised owners manual insert to all owners of the Gen III Prius. Fortunately, it doesn't work that way in the real world. Now Toyota has an obligation to objectively research the brake issues with Gen II and I cars and if there is an issue, fix it. Nothing more and nothing less.

 

I owned a Gen II , 2007 for 3 years and i experienced the ABS brake issue and in my opinion there isn't really any issue it just a bunch of people being anal and not understanding what is happening. OK so shorten the delay on the Gen III because it is a little longer then in the Gen II, i mean geezeee, people grow up. Yes its a quirk in the way the machine works get over it, its not a safty issue and deesn't deserve all the bad press its getting.

Read your owners manual and act like an adult.

 

And what qualifies you to make the determination that it isn't a safety issue? Do you have a Ph.D in vehicle safety analysis or some related discipline? Or, perhaps you stayed in a Holiday Inn last night?

 

Yes I do have a college degree in mechanical engineering and 30 years experience in solving manufacturing quality problems in industrial gas turbine production, but no i don't have a PH D in vehicle safety but my experience has shown me that common sense often outweighs education. The Gen III brake delay is 700 milliseconds, the Gen II delay is roughly 1/2 of that. I don't have the exact details but i suspect the Gen III delay was shortened to what the Gen II currently still is.

Tell me what have all the Gen II people been doing for the past several years if the Gen II issue is so important and a safety issue. How many complaints have been logged with the government, how many accidents have occurred due to this issue???? The Gen II has been in production for several years so there must be a ton of evidence going back several years that you can list to support your claims???

 

I was going to stay out of these discussions, but some of this is getting just plain silly.

I've been driving since 1972, and I can categorically state here and now that the Gen II Prius overall behavior is no worse than most other cars in it's size and weight. In fact, I found that it's performance in snow and ice is better (by a fair bit) than my 2004 Chevy Cavalier, or my 2005 Corolla. Regardless of whatever car one drives, it is the responsibility of the owner to learn the car's strengths and limitations.

What appears to be happening here is a lot of people are convincing themselves that the Prius behavior is somehow less safe than other cars, and that is simply nonsense.

I cannot tell you how many times I've seen cars (and especially pickup/SUV) in bad weather spin out, crash, etc. In almost all cases, the drivers were not driving defensively. Just because a vehicle has 4 wheel drive does not mean it is immune from spinning out or skidding in bad weather.

Every car that I've ever owned with ABS has a different set of behavior characteristics in slippery/bad weather conditions. One simply needs to understand them and drive accordingly.

When the police first shifted over from rear wheel drive to front wheel drive cars, there was a large spike in accidents with them. The police had to re-learn how to drive to adjust to the different behavior of the cars.

There are a LOT of bad drivers up here in the North (especially in NJ, which has the highest insurance rates in the country). I think a lot of people are jumping on this brake issue out of context, and perhaps need to look at their driving habits vice blaming the car.


So, I do not believe that the Gen II is bad in adverse weather conditions. I've owned a Prius since 2006, driving up here in New England winters, and it is a better car in bad weather than my Chevy or my old Corolla.

My only issue with the Prius is the OEM tyres are not so good, so I switched them out with the Nokians, which helped out immensely.

 

freo, thank you for expressing your opinion. When you have some facts to share I would appreciate that too.

 

I would have thought that your education and work experience would have made you aware of the risk of extrapolating beyond factual data points. You don't know what the Gen II delay is; how can you conclude that the Gen II has the same delay as the Gen III?

Perhaps they have been intimidated - either at the dealer when the SA told them they were imagining the condition or on forums when they were told that they were dumb and they should RTFM? There are threads on PC that go back to something like 2007 about brake system issues. It is not as if this just decided to rear its ugly head on the heels of the Gen III brake issues.

You acknowledged the presence of a lag in the Gen II cars. Now the debate has shifted to whether the lag constitutes an objective safety issue. I am willing to let an objective expert (NHTSA) make the call as to whether it is in fact a safety issue. What I am not willing to do is to let non-experts hold forth about how people should RTFM and that the delay is not an objective safety issue in the absence of any finding of fact by an objective expert.

 

Check out a quick search of ABS brake problems from Toyota, GM, Chrysler, etc.

ABS brake problem recalls - Bing