I don't know what you mean by "hydraulic direction hardens"

1. check the coolant overflow reservoir. If it is empty, then there is not enough coolant. You will need to add coolant and check for leaks.
2. a common issue is the radiator cap is worn and does not hold enough pressure. This will lead to overheating. A new radiator cap is the simplest and easiest repair. Make sure you have the proper radiator cap for your car.
3. The radiator has an electric fan. when the car gets hot, the radiator fan should automatically turn on. You may need to open the hood to listen to the fan. You may also be able to see if the fan is running, but don't put your hands inside the fan housing. If the fan is not turning on, then you will need to check fuses and relays to see if they are the problem. Check your owners manual to find the fuses. If the fuse and relay are good, then the fan is the most likely problem.