An auger airlock assembly and end dump housing having a spring loaded bottom for use in a bulk loader which utilizes a source of negative pressure to create a suction air stream that draws particulate materials into the loader for transfer, via the auger assembly, to a location remote of the loader. Materials exiting the auger assembly accumulate within the housing to a point wherein, once the accumulated material has acquired a certain weight, the bottom of the housing is forced open to permit discharge of the material, and, once the material is removed, and is not present in enough quantity to maintain the bottom of the housing to remain open, the spring loaded connection biases the bottom back into a position sealably closing the housing. The bottom of the housing may also be opened by the auger feeding more material into an already full housing, whereby the material is compressed so as to force the door open. Side portions of the housing limit the opportunity for outside air to enter the airlock assembly during the discharge of materials, maintaining the vacuum suction created by the negative pressure in the auger assembly.