a very common fault on most cars. you will need to strip the brakes and clean them.sometimes the brake pads glaze and go smooth so you might need to replace them or do what i do and rub them with sandpaper to ruff them up put copper grease on the back of the pads and any pad retainer pins and that should do the job.but if your not sure what to do then i recommend getting a garage do it as you cant take chances with brakes.hope this helps
mikey11000
July 2007