Diagnose break noise from front D-side wheel
I know this post could be very vague and hard to determine the "exact" cause of the noise but I will give it my best to describe this problem with the utmost detail to help whoever reads this.
I'm a fairly new Alfa owner, just moved to Italy and enjoying my stay so far. The problem is the left D-side wheel. When I'm traveling on the Autostrada (Highway), There is a high pitch noise coming from the wheel. The noise is not constant and it comes and goes as my speed changes and turn to change lanes. The noise only occurs when I'm traveling for a bit above 80km. when I reduce my speed and I'm traveling through local towns, no noise is heard.
How do I know its the breaks? As I am driving and the noise begins to occur, I press the brake and the noise suddenly stops. It stops for a good 15 seconds before it begins to pick back up again.
I brought my car to a local mechanic who speaks a little bit of english and he drove my car but never above the 80km. The sound never occurred but my breaks squeaked (that's another issue I'll bring up). He told me that it was probably my break line going to the wheel, whenever I release my foot off the break, the pad doesn't fully disengage causing the noise that I'm hearing. He also said that it couldn't be my pads because my pads were not worn and fairly new. So, he changed the break line in both my wheels, I headed back out on the road and the noise is still occurring.
Now I will try to describe what I'm hearing exactly. I can start by telling you what it doesn't sound like. Its not a grinding noise, like metal on metal and I do not feel anything on the pedal. I've had pads and brake issues before in a different car and I actually felt it on the pedal, but not this issue. The noise comes and goes, there is a high pitch sound to it like some thin piece of something is dangling or hanging. I've tried recording the sound but there is too much wind in the microphone. Its a very annoying sound while I'm driving and I want it to go away.
If any of you might have an idea of what could cause it, please reply with a picture of what to look for and I'll fix it and experiment with your suggestions. Also, if you have a question I will answer it to the best of my ability given the limitation of you not being here. I could of easily left something out that I didn't think of typing down but you experts will probably remind of that..hehe. I appreciate your time in reading this.