I had a recent brake problem where the brake felt spongy, light and I couldn't get the full brakes I should have. I found a flexible hose was broken on the inside. The outer layer of the hose collected the brake fluid (like a baloon filling with water) when I pressed the brake pedal. When I let off the brake the outer hose would have enough pressure to push the fluid back into the system. No leaks. Replaced flexible line and now it's AOK.
