Hi new to forums and i am looking for help with a problem i have with my E Class E320. When i brake i get a thumping noise from rear louder the faster you go. It has been on an Ethos computer and this showed WSS front and rear Left. I bought 2 second hand ones but this did not fix the problem. Im wondering if it will be fixed if i buy new original ones but am worried that this also may not fix problem. Any advice would be gratefully received.