Hydrostatic drive agricultural or work vehicle, comprising: - a hydrostatic transmission unit, suitable for vehicle propulsion; - at least one service brake system comprising friction elements arranged to brake the vehicle in response to a braking request; - a user interface of the service brake, suitable for receiving said brake request from a vehicle user; - at least one spring-loaded parking brake system SAHR (SAHR), capable of exerting a parking brake action; - a controller operatively connected with said user interface, with said service brake system and with said spring parking brake system SAHR and configured to detect a failure of the service brake; wherein said controller is configured to automatically activate said SAHR spring-loaded parking brake system to complement said service brake system to perform an emergency braking in response to a brake request by the user in conditions of service brake failure; the vehicle being characterized in that - the hydrostatic transmission unit is configured to create a hydrostatic braking system to exert a braking action on the vehicle and in that - said controller is configured to automatically and simultaneously activate said SAHR spring-loaded parking brake system and said hydrostatic braking system to complement said service brake in response to said braking request by the user to perform the emergency braking in response to said brake request by the user in service brake failure conditions. - a hydrostatic transmission unit, suitable for vehicle propulsion; - at least one service brake system comprising friction elements arranged to brake the vehicle in response to a braking request; - a user interface of the service brake, suitable for receiving said brake request from a vehicle user; - at least one spring-loaded parking brake system SAHR (SAHR), capable of exerting a parking brake action; - a controller operatively connected with said user interface, with said service brake system and with said spring parking brake system SAHR and configured to detect a failure of the service brake; wherein said controller is configured to automatically activate said SAHR spring-loaded parking brake system to complement said service brake system to perform an emergency braking in response to a brake request by the user in conditions of service brake failure; the vehicle being characterized in that - the hydrostatic transmission unit is configured to create a hydrostatic braking system to exert a braking action on the vehicle and in that - said controller is configured to automatically and simultaneously activate said SAHR spring-loaded parking brake system and said hydrostatic braking system to complement said service brake in response to said braking request by the user to perform the emergency braking in response to said brake request by the user in service brake failure conditions. - the hydrostatic transmission unit is configured to create a hydrostatic braking system to exert a braking action on the vehicle and in that - said controller is configured to automatically and simultaneously activate said SAHR spring-loaded parking brake system and said hydrostatic braking system to complement said service brake in response to said braking request by the user to perform the emergency braking in response to said brake request by the user in service brake failure conditions.