Hi. I have a 2009 Toyota Sienna with approx. 130k miles. Recently I am noticing when driving on the highway that I get a humming/ringing sounds. It gets louder and softer as I drive. It is not always there but when it does make that sound, it is when I am over 65 mph. If I tap the brake it immediately stops but then if I hit the gas it starts again. Also sometimes when I tap the brakes (not on the highway) I do get a screeching sound. I’ve taken it to the mechanic and he checked my brakes and says they are fine. I just got two front tires thinking it was that but it is still there. Is there anything else that I should consider? Should I go get a second opinion on the brakes since the sound stops as soon as I tap the breaks? Thanks!
BRAKES not breaks
I would suggest having a different mechanic check your brakes, as well as the wheel bearings.
The screech may be the from the accessory belts (A/C, Alternator, and PS). If they are the original belts it wouldn’t hurt to replace them after 6 years.
Brake grease could be added to the back of the pads to reduce the brake sqeal. Are the pads oem?
Try swapping the front and rear tires, see if the noise switches places too. First place to start on this kind of problem is usually the tires. Not b/c it is always the tires, but the tires are the easiest to eliminate.