Embarrasing brake problem.. normal?

Get the brakes checked out again.

SCH-I535 ? 2

 

Extremely common compliant. Its because the hydraulic brakes are not used much as alot of the braking energy is done by regen. Not alot of severe clamping of the brake pads against the brake rotor resulting in a build up of rust on the rotor making them especially grabby when damp out. This is exacerbated by not garaging the car.Without regen assistance the brakes are quite poor on this car.

Easy long term help is to routinely clean the rotors by putting the car in neutral (which removes all regen assistance) and at speed apply the brakes firmly like you have to stop soon 1/2 mile away. First time you do this make sure no car in front or behind you as you will be startled how poor the brakes are without regen.

Alot of us routinely do this. My rotors don't look to bad. Somewhat shiny. I'm so used to it its like second nature to slap it in neutral and just come to my next stop. Really helps.

Yours may be too far gone rusted. Get a flashlight and look between the front wheel spokes.

 

Agree, get it checked, it's a safety issue.

It may be one of the wheel speed sensors is bad, triggering the ABS. No dash alerts illuminate when this occurs?

 

did you go over a little bump or anything? My brakes would do that over a little bump when my foot was on the brakes.

 

Mine did the same during and even after a good rainstorm a month ago. I did the braking in neutral like edthefox5 described and the problem went away.

 

I've driven other cars that do pretty much the same thing, you just notice it more in the Prius because of the switch between regen and friction brakes.
When I cleaned mine, I got up to 35MPH, shifted to N, and pressed the brake with moderate pressure until about 25MPH. It really shouldn't take much to clean them unless they're really bad.

 

Remember !! You must hold the lever in the N position for 3 seconds for it to shift to N. Watch the dash gear indicator to make sure it indicates N before attempting the rotor cleaning.

 

Somehow on my 2005 Prius brakes are not "poor". They are very adequate even in neutral. And yes, grubbiness at 5 mph is due to rust on rotors from parking outside in rain.
Alex

 

Another thumbs up vote for the cleaning the brakes a few times via putting in neutral trick. Works every time.

 

Yup, I agree also. If it bothers you do the cleaning thing. After awhile you will get accustomed to it, and expect it. It is exacerbated if the Prius sits for several days between driving and also when the humidity is high or just after the dew has fallen, rain etc.

Honestly, I don't think it is a safety issue. Normally, the car tends to stop a little quicker when this happens. It just startles one who is not used to it.

You can clean the rotors as pointed out above, but you will have to do it more than once if you are in a humid or wet area. Remember you can't just slap it into neutral. You have to hold the lever in N for at least three seconds for the transaxle to shift to the N position.

 

Besides its a very good thing to know how to put the car in neutral in an instant to prevent a run away car.
Its second nature in all my cars. My other non hybrid cars I automatically put the car in neutral at a stoplight.
Easier on the trans.
In my Prius I do it quite often approaching a stop if the battery is already in green and to clean the brakes.
2 birds with one stone. My rotors look pretty good but still some base rust under the shine. Not anything like a normal car with super shiny rotors. I would imagine if the OP does as I requested he will find his rotors are really rusted and may need to be replaced.

This is one of the most common complaints here at PC that and the dead little 12 volter.

 

I live in the Northwest, and we get lots of rain.
So I can tell you with confidence that what you are experiencing isn't the norm.

There is a rather hotly debated and high profile reaction of the brakes that can happen under very specific conditions, that creates for some people the feeling of the brakes lunging. But what you are describing doesn't sound to me like that situation.

I've have used the brakes in rain conditions on pavement, manhole covers, slick spots...and never have they reacted in the manner you are describing. If this is happening you need to get them checked out again.

 

And what brand of tires are you running. Hope to god you don't have a set of GoodYear Integrities on the car.

 

Didn't have to wait long:

Brakes are too sensitive | PriusChat

 

I also thought putting the transmission in neutral was better as far as wear and tear until I read that it puts wear on the shift components.

I always shifted to neutral at stop lights in our Quest van. We started having transmission trouble and decided to get another vehicle rather than deal with potentially expensive diagnosis and repair of transmission problems.

 

The difference in the Prius is it does not shift gears at all, even for reverse.
The various modes, neutral, drive, and reverse are all mechanically the same. The only exception is park where the transmission is locked by a pawl mechanism. The rest of the transmission still remains the same as in the other three modes.

John (Britprius)

 

Thanks, I understand that. I was replying to the comment that he is doing it on his non-hybrid cars.

 

Sorry, my misunderstanding of your post.

John (Britprius)