We started to have this conversation under another thread but I'm curious if anyone else has noticed this. I can back out of my garage and look like a new manual transmission driver. My foot is naturally over the brake but not touching it. The brakes will do a quick grab and startle me and anyone in the car. It takes pressing the brake pedal a decent amount (not enabling hill start assist) and then I will drive again without an issue. I see it most around cold starts. Is anyone else observing this behavior? It seems to be more regenerative brakes than mechanical but I can't be certain of that from the driver's seat. The decline in my drive way is very mild I'd guess 3% or less. The car has done this off and on since 300 mi with 1k now. Dealer can't reproduce. W
Once in long while (maybe 5~6 times in 18 months of ownership) when backing up after start up, our brakes are very grabby. This is a regular Prius, but very similar to your description. First time it happened I was backing up to get out of parallel parking space: applied brake and the stop was so sudden I thought I'd hit the guy behind.
I thought the same on hitting something. Did your dealer have any ideas? I've had it about 3 times in 2 months of ownership. I'm guessing it's a software issue but I'd really like it fixed. W
My v has the very same behavior sometimes when backing up. I actually have some rubber marks on my driveway.
Wanderer thanks for starting this tread. It's sounding like a nuance of the regenerative brakes. Anyways, add me to the list of grabbing/clunking breaks. Please keep us posted if anyone hears of a fix.
I used to have this problem frequently when I first got the 2010 Prius. However, ever since I discovered the trick of letting go of the brake completely and re-applying it (which cures the grabbing brakes syndrome) I've sort of adjusted how I modulate the brake pedal over time and haven't had this problem occur in a couple of years. This is just something you learn to avoid over time by adjusting how you modulate the pedal.
That's a depressing thought spiderman. How long have you been aware of this? It's my first Prius so it's all new to me. W
Man I need to proof read my stuff better. Anyways, my brakes did this a couple times shortly after I got it (in 09). I haven't had it happen since. Perhaps it is just related to new brake pads/rotors?
The Prius brakes are used so infrequently that rust becomes a problem even when new. One thing you can try is, in a safe area without traffic in front of you, when you are slowing for a stop light put the car in neutral. This disables the regen braking and forces the friction brakes. This will help clean the brakes and the rotors of any rust. Try this and see if you see any improvement.
It would be interesting to test this theory by asking if anyone has experienced the grabbing brakes syndrome on a used 2010/11 Prius they just bought. If they do get this syndrome, then it's just how new owners modulate the brake pedal and it's a learning curve to eliminate that.
^ Good question. Although I wonder if some people might be mixing two different events. I know the brakes get real sensitive when the rotors are rusty... but that is quite different from what I felt twice (going in reverse). In fact one time, I drove quite a distance (many downhills included), went into a grocery store (15 mins), backed up and they grabbed like nobody's business. My wife thought I was goofing around, it was so dramatic.
I experience this phenomena with my v mostly in parking lots either backing up or pulling out of a parking space.
I have had my Prius v for 5 months. I have experienced the grabbing brake problem 3 or 4 times, always when backing up. When it last happened to me a couple of weeks ago, I put the car into neutral, then back into reverse. This cleared the problem.
^ sorry to hear about the problem in your first post. I haven't heard anyone complain about the problem (the one when the pedal sinks and gets hard) more than a year old. Hard to say what the problem is.
