Did you bleed the entire brake system, or only the rears?
Brake fluid is supposed to be replaced every two year to remove contaminates, moisture, and wear particles from the system. It takes at least 1.5 quarts of fluid pumped through the system to flush it properly.
If you did pump that much fluid, then there should be any air in the system, and the odds are that the master cylinder is shot.
You can get a new Meyle master cylinder for about $45-$50 with free ground shipping from several aftermarket sellers.