Prius makes "toot" sound upon cold startup

I got that sound from my 2006, but only when I was traveling out west last fall. I assumed it had something to do with the higher elevation and temperature variations. Mine sounded like the brake accumulator or master cylinder. I had the dealer check it when I got back, but by then it was quiet.

Tom

 

I think you need to stay out of Arizona! It's placed a hex upon your car Patrick.

 

Is it supposed to be silent when you press the brake on startup? My 2007 makes a whirring noise when I step on the brake to start it.

 

Boost pump? Accumulator? I know an FJ owner (The FJ also has electric assist brakes) and he happened to notice that noise when starting up in his garage, hitting the brakes, and backing out

It was LOUD as he could hear it over the motor

Dealer changed the entire brake boost/cylinder assembly under warranty. Apparently it was some sort of defect, hasn't made the noise since

 

Isn't this the brake actuator noise that's been refered to many times? If so it is harmless.

http://priuschat.com/forums/toyota-.../29211-tsb-br001-07-brake-actuator-noise.html

kevin

 

Harmless perhaps, but irritating as it gets worse and happens whenever the brake pedal is pushed. My 2004's "Toot" was eliminated (air bubbles removed) by bleeding the right front brake (at the dealer as a specialized computer interface is required).

JeffD

 

That's what was making the noise in my car. The actuator was replaced just before the 3 yr./60,000 km warranty was to expire. Start ups now are nice and quiet.

 

that's the tsb issue. others have called it "barking" or "honking" or whatever. we had it, that's why DH replaced the actuator.

 

Patrick

I have had this toot the last few days when I startup and yes I ask my wife if it was her. My wife always says its not me even if it is.

I shut off my baby when I got home and then started it up but it did not occur again.

I have had my baby for 1 year now and this is the first time (the last few days) I have heard this toot.

I was doing a search for this noise when I found this thread.

Chuck

 

I have a 2008 and I've noticed recently that my car makes an infrequent, random sound like a very low horn toot when I first start it up and it is still in Park. I have around 11k miles on it. I will mention the sound to the dealer when I take it in for its next standard service appointment. I'll ask about the actuator. I do not have an after-market alarm system and I don't think the sound is actually the horn. It's more like a low squeak - not constant - just occasional. It goes away when I put the car in Reverse and then Drive.