Solid caliper leads to the soft pedal?

Hey, I drove to the TÜV with a car. I already thought that this vehicle did not exist the TÜV and wanted to check before I still invest something, whether it is worth it. In the end it is only a small thing: the brakes. The following defects: – service brake 1. axle uneven (over 25%) – service brake system minimum braking not achieved – wheel brake 1. axle left freedom of movement not sufficient Note: service brake 2. axle slightly uneven Measurements 1. axle li. 144 / re. 194 2nd axle li. 130 / re. 106 z = 41.9% So much for it. The brake at the front left does not go back in order. Vehicle: Built 1998 / 73,000km / 1 time a month It was inherited now and is driven more. The workshop now said that you can try to clean the brake and try it again. Nevertheless, I do not think that this will have a lot of effect. The brake pedal has been soft since the takeover and had no proper braking performance. I pushed it onto the The rear brake drums were changed and the system was ventilated. Nevertheless, the soft brake pedal was still present. I think there is something wrong with it. How would you proceed? Can a defective caliper lead to a soft brake pedal and the reduction of the braking effect in the entire system? (For example, air in the system)