New Prius, new sound

<div class='quotetop'>QUOTE(megs @ Jul 19 2007, 08:07 AM) [snapback]481498[/snapback]</div>

It's normal. I can't think of the right acronym for it, but I want to say it's the break pump. If you haven't noticed it, is more noticeable when you are going slow and you break. Maybe someone else has a better answer, but hope this helps.

 

<div class='quotetop'>QUOTE(megs @ Jul 19 2007, 07:07 AM) [snapback]481498[/snapback]</div>

<div class='quotetop'>QUOTE(chich2000 @ Jul 19 2007, 07:13 AM) [snapback]481502[/snapback]</div>

chich2000 is thinking of the brake accumulator pump. It's possible that this is what it is, but it should have been there the whole time. A way to check is to stop the car, put the car in park, and pump the brake pedal a few times. The pump should come on. Is that the sound you're hearing? If so, you're OK. If it's a different sound that you hear while braking, it could be something you should get checked out.

 

<div class='quotetop'>QUOTE(megs @ Jul 19 2007, 08:07 AM) [snapback]481498[/snapback]</div>

The brake accumulator pump usually pumps up about every third time you put your foot on the brakes. If you stop your car, turn off all accessories like AC and Stereo.....then put your foot on the brake pedal and push harder than normal you should hear the pump turn on(near your feet while driving). It is like a whirring noise. While we are on the subject of brakes...you will notice a slight difference when braking at near 7 or 8 mph or less when the friction brakes(brake accumulator pump forcing hydraulic fluid to brake cylinders) kick in. This is normal. Once in a while while going down hill less than say 50MPH and with no one behind you....you need to put your car in neutral..hold it there a second or two. Step on the brakes at this time to use friction brakes only to help clean the surface of rust and to help the breaks wear in. The friction brakes are only used when less than 7 MPH(above that it is REGEN braking) so very little use for these unless you do the above. All of this came from HOBBIT. You will have to learn to brake differently in this car as opposed to your not so perfect other car. There is a whole monster thread about 120 post long just on braking and some of the problems associated with it. It is worth the read. I have gain much insight about the Prius just reading about 2 hours a day on this site. Enjoy.
D Rock

 

just want to chime in

most cars with ABS will make this noise, especially prius because of regen braking

you really only notice it because the prius is a ninja=]

:lol: