Trouble keeping bleeder hose connected

"Speed Bleeders" is what you need. No air can get sucked back in. Russell makes them. An awesome product.

Russell Speed Bleeders let you bleed the brake lines on just about any vehicle all by yourself. Just replace the old bleeder screws with the Speed Bleeders. The Speed Bleeders have an internal check valve that will pump excess air and fluid out for you. A special coating on the Speed Bleeders' threads keep it from admitting air into the system, and keeps expelled air and fluid out. When you're done, just tighten the screw and go on the the next brake cylinder.

5/16-24 thread p/n 639530, 3/8-24 thread p/n 639590