Hello everyone I am experiencing a noise that sounds like it might be comming from the master cylinder in the braking system, but i am not entirely sure. the noise happens seemingly random but i am always braking a motor noise of some sort. I can't hear it in my friends 06' Prius package 8 but i definately hear it in mine 06' package 3. Any ideas what it is? Am I paranoid or is this somthing i should be concerned about? It sounds similar to the "whirling/click noise" post however this isn't a click noise... http://priuschat.com/index.php?showtopic=22460
I would recommend you take it to your Authorized Toyota Dealer for proper diagnosis and repair if necessary.
Oh f'krissake. Dealer, schmealer. In support of possibly one of the most common newbie questions -- if anyone with fewer than, say, 100 posts asks this, then it's the accumulator pump, period. If the poster says "I know an accumulator pump when I hear one and this ain't it", then start worrying. . Zerk -- it's the accumulator pump. Translation: braking is done "by wire", meaning that your foot doesn't push hydraulic pressure out to the wheels but a bunch of electronics and valves do. But that system has to get pressure from somewhere, so what the Prius has is an electric hydraulic-fluid pump that builds up a bunch of pressure and holds it for whenever it's needed. As that pressure gets used up or bleeds off, the pump automatically runs to keep it up to a usable level. . If you want to hear a lot of the same noise, stop the car someplace quiet and pump the brake pedal slowly but firmly, up and down. You'll hear a whole lot of pump activity as it keeps up with usage. . You may also hear a burst of it just when you put your foot on the brake to turn on the car, too. . Now, after all that, if that *isn't* the noise you're hearing, suddenly it gets more interesting... . _H*
<div class='quotetop'>QUOTE(hobbit @ Aug 18 2006, 07:47 PM) [snapback]305650[/snapback]</div> Just got mine, and I hear that noise, too.