Hard brake pedal

Good afternoon:
I have a Citroën C4 HDI 110 CMP, when I leave the car in the parking lot at night and I am going to take it in the morning the brake pedal is completely in the upper and very hard part, I will go to the workshop since I still have it in guarantee, but I want to know more or less that it can be so that it does not lie in the workshop

It seems to me that you have an empty loss somewhere in the assistance of the brakes. When you leave the engine off, air enters so it loses the void that causes the Cervo to help the pedal stepped on. Without that assistance the pedal is hard, above and does not stop almost anything.

Thank you very much for your help, is it dangerous, or can I wait a few days to take it to the workshop?

When there are problems with the servo brake, it is not very dangerous but at the time of stepping on it it becomes very hard and you have to practically stop on the pedal to stop, it remains as a mechanical brake of a thousand years ago the vehicle stops but feels like not.

You must check the empty hose of the hydrivatt if it is not bad it has the bad diaphragm of the hydrovat or a stamp