Brake pedal - braking fault

[newuserhere]

What are your thoughts....

Brake pedal has a lot of travel to floor before biting. If I pump three or four times it starts braking a lot higher and feels normal. Within seconds though back to how it was before..
It's like this stationary and driving with engine running.
Pedals rock solid when engine off and stationary.

[newuserhere]

1.2 clio
Drums

[newuserhere]

I would have though master cylinder would cause a soft pedal when pressed all the time

[newuserhere]

If seals in master cylinder were letting fluid back you'd see fluid passing back at all times so pedal would sink

[newuserhere]

I think tbh my problem will be rear brake cylinders seeping out but was wondering what others thought