LC200 Brake issue

[sandymarky11]

Hi bought a second hand 200 series and love the truck but have an annoying vibration through the brake pedal. It doesn't feel like the normal warped disc as very fast, more like ABS feedback its also intermittent. Sent the vehicle into my local main dealer who replaced the brakes and it seemed to be gone when I collected the vehicle but has now come back intermittently ,any ideas what it could be ?