Thought I might share this in case it may help others with the same problem.

A short while back I decided to repaint the brake hats on all 4 corners and at the same time clean the inside of the wheels(OCD). At the same time, look into the vibration at certain speeds and under braking.

The first thing I noticed while removing the wheels was at least 2 nuts on each wheel seemed to be catching as they came off.(strange)

Secondly, the front rotors had black rings around the face.(drilled rotors)
Closer inspection found all the holes blocked solid with brake dust.

Before painting I went round all 4 and cleared all the holes. After the paint dried it was time to refit the wheels. First checking that all nuts spun down the studs freely.
I then carefully refitted the wheels and made sure that all the lug nuts went home correctly which they did.

I must add that all wheels are undamaged, run true, are balanced correctly and that tyre pressures are as per the book.

Took the car out for a spin and was surprised to find that the braking had now returned to the smooth action it once was and that the vibration at given speeds had also disappeared.

Returned home and the rotors are now also shiny with no black rings.

Upshot of this is now I shall add cleaning the rotor holes to my OCD list and any time the wheels come off by a third party, I shall take them off and put them back on again just to be sure.

For anyone with the same kind of symptoms, I would always say, check the basics first before you throw your hard earned at it.

Hope this may help in any small way.

 

Good advice, the simpler stuff can easily be dismissed or overlooked.

 

Interesting. I have cleaned my discs with compressed air in the past, though the mysterious wobble that's been on the car since I got it over two years ago, seems to be getting worse. Thanks for the idea, though.