Gilessmummy

Hi all, Ive got a 2012 CRV It’s not been driven for a few months and when I took it out today I noticed a thudding noise when pressing the brakes. Like a du du du sound.. it ‘ seemed’ to be coming from rear passenger wheel area Any clues as to what could be causing this? Is it an expensive garage fix. I’m not capable of doing it myself... T.I.A