Apart from the usual air in the brake system that requires bleeding (note that there are up to 3 separate bleed screws on the brake master cylinder alone for master, ABS and TRC if fitted), a corroded and seized sliding pin in the front disc brake may not allow the brake calliper to slide as designed. A tell-tale sign is when the first application of brakes feels spongy and the next application immediately after the first has a firmer feel. (New dust boots and sliding pins for early LS400 do fit early SC400 and Soarers).