Rear rotor continuous squeel(k)

[grummor]

Mountain bike with disk brakes.
When riding, there is a LOT of noise coming from the rear disk brake WITHOUT using the brake. the noise happens during the ride, using the brake, or partially using it, helps for a bit, but the noise gradually becomes worse.

The squeaking isn't produced when i'm not on the bike, and is sometimes lessened when accelerating or going over bumps.

I have no clue as i am very new to the entire disk brake concept however here are some things that i find strange:

-the rotor(?) seems to touch the brake pads(?)
-when braking it seems as if the rotor (the disk that passes between the pads) is being bent out of shape , and then returns to initial position when braking is over.
-no clue in what state the braking pads are or how to maintain them.
-squeaking gets better after washing/rain, but gets worse when dried and the longer the ride the worse it gets.
-A different kind of squeaking happens sometimes when i brake but it's a lot clearer, like a note played on a n instrument rather than an angry sound.


ANY suggestions ? what could cause this ?

note again.
Squeaking occurs when i'm NOT using the brakes.

Thanks in advance for any insights.

[nfmisso]

The huge advantage of disk brakes: everyone can here you coming from the squeak/squeal.....

For the brakes to work (at all) that pads have to be very close to the rotor even when not braking. It is a tricky adjustment. IF the rotor is warped, it is next to impossible, sometime impossible to adjust out the noise.

The water acts as a lubricant.

Make sure that the rotor and the caliper are correctly positioned, and all fasteners are torqued to specification (too little and things wobble, too much and the caliper might seize or worse you strip threads) - REQUIRED: torque wrench.

Redo the adjustment per the manufacturer's technical documents.

[1FJEF]

Also is the rear wheel "straight" in the frame? leaning at the top? Off center?