Could be a bad brake hose, possible abs pump. A hands-on inspection is needed before you replace any more parts.
Use this link to find a good shop near you.
https://repairpal.com/repair-shops
Alex
RepairPal Certified shops can diagnose and repair your 1999 Lexus ES300. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.