Rear passenger side brake scraping noise? after carwash

[Alex Ratcliffe]

Hi

Yesterday car and brakes were working perfectly, i took the car to the local ARC car wash and after the wash the back side rear passenger brakes have not stopped making this scraping noise each time the brakes are applied.
I am aware they spray the wheels with foams and different liquids, but these surely would have dried by now? and i doubt they would encourage this kind of noise.

Any ideas on what this could be? could the car wash itself have knocked something out of place?

Any help would be much appreciated

Thanks
Alex

 

[aucky]

Probably just oxidised the disc. Some heavy breaking will clean them up.

 

[raviedavie]

Probably just oxidised the disc. Some heavy breaking will clean them up.

That would be my first move

 

[Paprika123]

Are the rear pads still present?

 

[Alex Ratcliffe]

rear pads only 3 weeks old

 

[Alex Ratcliffe]

had a look at the disc and there is s a greeny off color on the disc all others perfectly silver and shiny no marks.
should i take the wheel off and give it a little rib down with something ive driven the car for about 50miles now just seems to be getting worse?

 

[flebay]

stones and grit in the calliper or pads, all it can be.

 

[Alex Ratcliffe]

gave the disc a little clean it looks better and went for a real hard drive but still the same grinding noise