An automatic deactivation mechanism is configured for an air bladder pump having a casing and a motor located therein to pump air into an air bladder from the atmosphere and through an air valve connected through the casing. The automatic deactivation mechanism includes a housing positioned within the casing and has defined therethrough a first aperture in fluid communication with the atmosphere through the casing and a second aperture in fluid communication with the air bladder through the casing. Included within the housing are at least two switches and a diaphragm positioned between the switches. The housing is sealed so that when a threshold pressure is reached therein, at least one switch is triggered by deflection of the diaphragm to automatically deactivate the pump by de-energizing the motor.