Squeaking / vibrating rear disc brake

[jonwm]

Afternoon all

Fair weather rider here and have an on older GT Aggressor XC3, its too good to get rid of and now my son has started riding we are getting out a bit more.

I've got the most annoying deep squeel / vibration noise coming from the rear disc, you can also feel it through the frame, to try and cure I have done the below:

New disc and pad used brake cleaner on disc- solved for 10 mins or so
a different brand disc and new pads, used brake cleaner - as above
a different brand of pads cleaned the disc prior to fitting - back again

Annoying the front is silent and is the original disc and pads, cant think what else to do.

Brakes are Tektro Auriga comp with hydraulic fluid.

Any help appreciated

[Scoobyshue]

Have you tried re-aligning the caliper?

[jonwm]

Scoobyshue said:

Have you tried re-aligning the caliper?

Only when putting the new pads in last time, I left it loose then pressed the brake lever the tightened it, if that's not aligning it then no

[Scoobyshue]

I'm out of answers then....sorry.

[bobbo89]

Maybe a very slightly sticky/leaky piston that's allowing a small amount of brake fluid to contaminate the disc and pads whilst also not centring properly when the brakes is applied causing the vibration?

[Scoobyshue]

There's a new video upload on GMBN Tech / Youtube on how to look after your disc brakes. Might be worth searching that.

[Fluffsri]

Try flipping the disc, sometimes this can help.

[Pickled Piper]

You have got some resonance going on. Try removing the calliper, cleaning the mounting area (use a smear of copper slip or similar here), greasing the mounting bolts and refitting.