Brake pedal dropping to floor

[Vince30]

Shouldn't be related to your booster. If you are not loosing brake fluid then most likely fluid leaking past the piston seals in the master cylinder. It would sink if pressing lightly and would stay if pressing firmly?

This is right on

[325issguy]

Sounds like you need to try to rebleed your brakes.

[whodwho]

Shouldn't be related to your booster. If you are not loosing brake fluid then most likely fluid leaking past the piston seals in the master cylinder. It would sink if pressing lightly and would stay if pressing firmly?

[Aatos]

I'm using a 944 booster and the brakes work fine. The issue is that when waiting on lights etc with foot on brake, after a while the pedal softens and drops closer to the floor. The brakes don't disappear though, you just need to push more.

Has anyone had this problem? I'm suspecting some sort of leak in the booster diaphram but it would be great to get some input before I replace it.