A park release valve for a trailer vehicle having a truck and a trailer and having a pneumatic brake system , and for controlling an emergency braking modulator (EBM) and/or spring-loaded brakes (SBA) of the trailer , comprising: a valve housing , a moveable valve element , and a push-button attached to the valve element for moving the valve element relative to the valve housing , the valve housing comprising: - a supply port (1-1) for receiving a supply pressure (p1) from the truck ; - a reservoir port (1-2) for connection with a trailer reservoir ; - a delivery port for providing a brake pressure for at least an emergency braking modulator (EBM) and/or one spring-loaded brake (SBA) of the trailer ; and - an exhaust port for releasing pressure to the atmosphere; and the valve element is moveable into at least three positions (V1, V2, V3), wherein - in a parking position (V1) the delivery port is in communication with the exhaust port ; - in a driving position (V2) the delivery port is in communication with the supply port (1-1); and - in a release position (V3) the delivery port is in communication with the reservoir port (1-2); and wherein when the supply pressure (p1) exceeds a predetermined threshold value, switching in the release position (V3) is prohibited, characterized in that the valve element is formed as a valve spool having at least one land and at least one valley , wherein the valve housing defines at least a first chamber , a second chamber , a third chamber , a fourth chamber and a fifth chamber between the valve spool and the housing , which are selectively closable by moving the valve spool a valve housing , a moveable valve element , and a push-button attached to the valve element for moving the valve element relative to the valve housing , the valve housing comprising: - a supply port (1-1) for receiving a supply pressure (p1) from the truck ; - a reservoir port (1-2) for connection with a trailer reservoir ; - a delivery port for providing a brake pressure for at least an emergency braking modulator (EBM) and/or one spring-loaded brake (SBA) of the trailer ; and - an exhaust port for releasing pressure to the atmosphere; and the valve element is moveable into at least three positions (V1, V2, V3), wherein - in a parking position (V1) the delivery port is in communication with the exhaust port ; - in a driving position (V2) the delivery port is in communication with the supply port (1-1); and - in a release position (V3) the delivery port is in communication with the reservoir port (1-2); and wherein when the supply pressure (p1) exceeds a predetermined threshold value, switching in the release position (V3) is prohibited, characterized in that the valve element is formed as a valve spool having at least one land and at least one valley , wherein the valve housing defines at least a first chamber , a second chamber , a third chamber , a fourth chamber and a fifth chamber between the valve spool and the housing , which are selectively closable by moving the valve spool - a supply port (1-1) for receiving a supply pressure (p1) from the truck ; - a reservoir port (1-2) for connection with a trailer reservoir ; - a delivery port for providing a brake pressure for at least an emergency braking modulator (EBM) and/or one spring-loaded brake (SBA) of the trailer ; and - an exhaust port for releasing pressure to the atmosphere; - in a parking position (V1) the delivery port is in communication with the exhaust port ; - in a driving position (V2) the delivery port is in communication with the supply port (1-1); and - in a release position (V3) the delivery port is in communication with the reservoir port (1-2); and <EOS>