Constant long beep - brake pedal pushes back

Time to have your car towed to your local dealer for service. Sounds like a problem with the brake actuator assembly.

 

I agree with Patrick. One of my Prii exhibited this behavior when the actuator was beginning to fail. If your brakes work fine after a moment (mine did), you're probably safe to forego the tow. Even if you lose hydraulic pressure while driving, you can still stop the car. I would just advise you to get it fixed sooner than later and, at all costs, avoid situations where you may need to slam on your brakes, as it could result in a loss of pressure and braking power.

If you never get your brake assist back after waiting/pumping the brakes, get a tow. Like I said, it's not impossible to stop the car without the actuator functioning properly, but it's most certainly not very safe to drive that way either.

Long story short, get it fixed as soon as you can.

 

Of all possible brake system problems, there are only a few for which the computer is programmed to both light the dash light and sound the continuous buzzer. Those are more serious and whichever one you have, you won't want to drive around much before fixing it.

The problem and the fix could be expensive or inexpensive. If you would like a better idea what you'll be getting into in your case, the codes from the brake computer will help. You can use a code reader like Mini VCI, which is easiest, or have the codes blinked out for you on the dash. You can do a forum search for posts explaining that.

-Chap

 

i just got a used 2008 Prius and had the same issue, break lights, ABS and all were on and while i was driving the long beep started and would not stop until i shut the car off. even with the car off, if i pressed the break it would give that same beep and it would feel like the break was pushing back. i had lost about half of the breaking pressure. i took a risk and drove it home and after a couple miles the beep stopped and i got full break pressure but all the lights were still on.

i checked the break fluid and found it was dirty, i mean green in color dirty. my friend and i drained the break fluid and then filled with new CLEAR fluid and then bleed the rear breaks (both sides). Also discovered there was air in the lines. After fully bleeding the breaks and changing the fluid we drove around for about a mile and all the lights went away. problem fixed.

jst wanted to share this before someone tows to a dealer and gets charged a few hundred bucks for a 10 dollar fix.