Spray 5- to 6-quart slow cooker with cooking spray. In cooker, arrange brisket pieces, fat side up. Add remaining ingredients except noodles and tapioca in order listed.
Cover; cook on Low heat setting 8 to 10 hours.
Cook and drain noodles as directed on package. Meanwhile, remove brisket from cooker and place fat side up on cutting board. If necessary, scrape off any fat from brisket and discard. Using 2 forks, coarsely shred brisket.
Stir tapioca into liquid in cooker. Return shredded brisket to cooker. Increase heat setting to High; cover and cook about 15 minutes longer or until thickened. Serve stew in soup bowls over hot noodles.