[Devildog2020]

My son has a 2005 CRF70, when he is riding and applies the rear brake there is a clicking sound that come from it. Not to sure what could be causing it.

[JimDirt]

Welcome to the site !!

Have you removed the wheel and pulled the drum off and looked at the brake shoes ???? ..... my guess would be the shoes are worn down , or one of the shoes has separated from it's backing (they are glued on or sometimes riveted) or it is worn to the point that the backing plate is rubbing on the drum or the rivets (if present) are rubbing the drum , pull the rear wheel so you can see the brake shoes and inside of the drum and even try to operate them manually while the drum is off to visually inspect them to see if something is not moving right , or if a spring is broken ..... it should not click or make any sounds , so something is definitely not right with them ....