Felt the brake cut-out thing.....

It is a bit disconcerting the first time, but it actually takes less than 1/2 second before the friction brakes kick in.

 

I have had this occur on my previous 2005 Prius AND my current 2010 Prius.

Personally, no other vehicle I own or have owned have ever had this response.

And, I don't care whether it is a 1/2 second or whatever for the brakes to engage, I don't like it one bit.

My two biggest gripes with the Prius...the brake cut out going over a pothole, and the damn rattle in the "skybridge" console which I can't get rid of.

 

But you bought another one. :madgrin:

 

Yah, next time I think about buying a new Prius I need to find a street riddled with potholes to I can check and see if the brakes cut out when I go over one.

What a ridiculous statement "you bought another one".

Toyota needs to fix this problem, as it has persisted from one generation to another. As I mentioned before, this doesn't happen in any other vehicle I have ever driven. It is specific to Prius'.

 

We have streets made of bricks. It has happened to me many times on several cars. Isnt it called anti lock brakes?

 

You didn't notice the goofy smiley? :madgrin: That's what I use to indicate that I'm not being serious.

However, the reason that it doesn't happen in any other vehicle that you have driven is because the others probably don't have regenerative braking + ABS.

 

Exactly my words . Prius is not an off-road car.

 

It behaves about the same as my previous car with ABS.

 

Absolutely--ABS releases pressure on the wheel that is locking so it will not skid, and then re-applies braking pressure to that wheel in pulses to maintain some degree of deceleration without lockup. If you have a locked and skidding wheel(s) you have lost some or all of your steering capability; ABS helps you maintain steering and braking by avoiding lockup. How many years has this had to be re-explained? Adding in regenerative braking hasn't changed the concept although it adds a second system that is being controlled.

 

I felt it the other day. The road was a bit wet, and I was braking, and I happened to go over a manhole cover that was not level with the road. It felt scary,...it teaches you to control your speed when it is wet out.

 

Well I can ASSURE you the Honda Civic Hybrid does exactly the same thing...Maybe that's why this wasn't earth shattering for me, because I am used to it. I traded in a 2007 Honday Civic Hybrid for my 2010 Prius V and It has only happened to me over a bump or similar and am used to it. The first time reminds you, then you realize .....

I use the analogy of slippery roads and the ABS kicking in, that's another scary momentary Stomach Wrenching experience (snow/Ice). But you learn that as well. I just don't tailgate and at least know what to expect....

 

Every car with ABS (which is all of them, for some years now) does the same thing. The Prius has the added jolt of cutting power to the wheels momentarily to protect itself. That sickening feeling is nature's way of telling you that you're driving too fast for conditions. Slow down.

 

I've had ABS in every car I've owned since the early 90's. I've felt the pulse and noise of ABS going off over a rippled surface. What my Prius does in similar circumstances is nothing like my prior cars with ABS. The brake just don't work for a second and the car actually seems to speed up. It is frightening.

 

Jimmy,

The two most pertinent words are "seems to" -- in fact, it does not speed up at all. I know about that of which you speak vis-a-vis "disconcerting", having felt the same phenomenon myself. However, knowing it's a sensation and not an actual issue (much like the sensation of the car "moving" when the ICE engages while the vehicle is in P), just means that I need to adapt myself.

 

For what it's worth, I have experienced that feeling in my Jetta GLI and Honda S2000. When driving quickly over a pothole, sometimes the ABS thinks that is wheel slippage since there is no road underneath the tire for that 1/2 a second.

If you were braking when driving over that pothole, the ABS disengages the brakes on the affected wheel to prevent the pseudo-skid that the car believes is occurring. (IMO)

You can also feel this happen when driving an ABS car with summer tires, in the snow.

I haven't experienced the brake cut-out thing in the Prius yet.

 

Ding, ding - we have a winner! ALL ABS systems work this way on EVERY auto. It has NOTHING to do with regen or the Prius. My favorite comments are ones like this:

"The road was covered with snow and ice, but when I hit the brakes, the car didn't stop!"

Advice: Learn just a little bit about how automobiles work before banging on the keyboard.

 

I do think the car companies are more than a bit at fault here-pretty much all of them--for public misunderstanding of ABS and how it works.
ABS advertisements always make it look as though ABS helps you stop more quickly, and in a shorter distance. That's simply false. It's not even what ABS is designed to do.
ABS is designed to keep you in control when braking in slick conditions. It does that, as others have noted here, by releasing pressure on the brakes during slipping, and then reapplying them automatically. Obviously, that cannot result in shorter braking distances than on dry roads, but it does prevent many skids.
I felt the same weirdness about it when I tried ABS out on gravel roads in my then-new 91 Subaru Legacy. Since I had never been told that ABS doesn't stop you faster, and didn't really understand it, I was a bit disappointed and disconcerted how it worked. (It was only when I burrowed deep into the owner's manual that I found any reference to the fact that it might result in INCREASED stopping distance--or at least increased stopping distance vs. normal stopping on hard, dry pavement.


Some years ago (but some years after ABS was introduced) insurance industry studies indicated that ABS didn't really cut down the number of accidents. At the time, I attributed it (without any evidence whatsoever, so sue me) to public misunderstanding of ABS--you still had to maintain at least the same distance between vehicles as you ever did. But that's not how it was--and is--sold.

I don't know what such studies would show today. But given that we see this misunderstanding continuing even among folks with above average interest in cars (given that we all waste so much time on Priuschat)--I'm going to bet that the actual benefits of ABS have not really been what they could have been had advertising for them been accurate from the beginning.

 

Actually, you're wrong - there are two separate issues I found with my 2010 Prius.

First, when the brakes are wet, the Prius over-compensates. I used to own a Corolla, and when the brakes were wet they would not work well for a few seconds until the discs dried off - then they engaged normally. I knew what was happening so I wouldn't over apply - I would gently increase the pressure until they worked, and then released pressure when they engaged, achieving a relatively normal decelleration. With the Prius, on wet days I get no decelleration or complete lockup as I back out of my driveway - like a drunk school kid on his first drive. This may continue one or two stops after, and then it's alright. This is not ABS - it has to do with wet discs and the car's software.

Second, I experienced this three times already (only 6K on my Prius at this moment) - sometimes when decelerating on bumpy roads, the breaks give AND the car suddenly revs up and accelerates! This lasts only a second or two, giving the car a jolt forward - and is very disconcerning when you're trying to slow down. Thankfully, I've only had this happen on the same local road just shortly after starting the car - I have never seen this on major roads (maybe because they're not bumpy?). I'm a little worried about driving the car in the winter (with all the ice and snow in Canada)... this needs to be solved.