knocking coming from brakes

there is a loud knocking coming from my brakes when i use them. no one knows what it is. any ideas

 

broken spring........time to investigate

 

most brake noise goes away when you apply the brakes...i would pull it down and check it out.
let us know what you find...

......

 

An out of round drum will do the same.

 

time to pull the wheels and check

 

thanks for all the replys .i have had every thing checked, even the bearings. but the drum not being compleatly round sound like that could be it. the faster i am going the gaster the knocking and the harder i push the louder. how could i check that and woul i have to get a new one.

 

Take it to someone who resurfaces them And have it turned. Thay will be able to see pretty quick if it's no good.

 

ok thanks