Brake Actuator Grinding/Screeching?

Hi Everyone!!

A couple of weeks ago I was driving down the road (45 mph) and came to a complete stop at a stop sign, and as soon as began to accelerate I heard this extremely load grinding/screeching sound coming from what sounded like my front end of my '08 Prius. I pulled over immediately to see if anything was dragging underneath or if anything was stuck in my wheel well.

My sister just so happened to be in her car behind me and she said that she heard the sound as well. I couldn't seem to find anything dragging or hanging down. I got back into my car and drove to the nearest parking lot (1/4 mile down the road from pulling over) - The screech/grinding sound continued the entire 1/4 mile. Once I stopped I put the car in reverse and heard the sounds for a couple seconds and then it stopped completely and I haven't heard the sound since.

I took my car to a local mechanic and they couldn't find anything that would explain the sounds.


After reading a couple of forums I'm thinking it might be my brake actuator? I know for a fact nothing was lodged in my wheel well or anything like that.


Any thoughts?


Thanks guys!

 

No lights at all. I haven't had any light other than a Maintenance Required light for oil changes.

 

I guess I should also mention that about a year ago I had been hearing what sounded like a large piece of metal knocking up and down. Which is what I originally thought when I heard this grinding sound.

I took it to Toyota Service and they said they couldn't find anything that was even loose, let alone dragging or hanging.

Not sure if the two situations are connected but I guess it's worth mentioning.

 

I mean it could have been? Like I said, I took it to Toyota and they said they looked at it pretty thoroughly and said they couldn't find anything out of the ordinary.

Would they have noticed if it was the heat shield fairly easily? Or would they really have to be looking?