A gas pump, preferably a negative pressure pump for supplying one or more assemblies, such as for example one or more assemblies of a motor vehicle, with a negative pressure, the gas pump comprising: (a) a delivery chamber comprising an inlet and an outlet for a gas; (b) a first housing part comprising a first sealing surface which at least partially surrounds the delivery chamber; (c) a second housing part which comprises a second sealing surface, which at least partially surrounds the delivery chamber, and together with the first housing part at least partially encloses the delivery chamber; (d) a delivery device, which can be moved within the delivery chamber, for delivering the gas; (e) and a pressing device (30; 40; 50; 60; 70) which presses one of the housing parts (1, 2) against the other with a pressing force, such that the sealing surfaces (6, 7) rest against each other and together form a sealing join which at least partially surrounds the delivery chamber in order to seal off the delivery chamber, (f) wherein the second housing part can be moved relative to the first housing part, counter to the pressing force, in order to be able to widen the sealing join to form a relief gap through which liquid situated in the delivery chamber can escape, characterised in that (g) a sealing recess extends around the delivery chamber in at least one of the sealing surfaces (6, 7) forming the sealing join, and the sealing recess is filled with a sealing liquid, preferably a lubricant for the gas pump, at least when the gas pump is in operation, in order to seal off the delivery chamber on its outer side, such that sealing it off by means of an additional sealing ring can be dispensed with, or a sealing element which is arranged in the sealing recess is elastically press-fitted when the housing parts (1, 2) are joined and thus ensures the necessary seal at the sealing join, wherein the sealing element is elongated and/or secured orthogonally with respect to the sealing surface (6, 7) in order to prevent the sealing element from being able to be carried along by liquid flowing off out of the delivery chamber when the sealing join is widened. (a) a delivery chamber comprising an inlet and an outlet for a gas; (b) a first housing part comprising a first sealing surface which at least partially surrounds the delivery chamber; (c) a second housing part which comprises a second sealing surface, which at least partially surrounds the delivery chamber, and together with the first housing part at least partially encloses the delivery chamber; (d) a delivery device, which can be moved within the delivery chamber, for delivering the gas; (e) and a pressing device (30; 40; 50; 60; 70) which presses one of the housing parts (1, 2) against the other with a pressing force, such that the sealing surfaces (6, 7) rest against each other and together form a sealing join which at least partially surrounds the delivery chamber in order to seal off the delivery chamber, (f) wherein the second housing part can be moved relative to the first housing part, counter to the pressing force, in order to be able to widen the sealing join to form a relief gap through which liquid situated in the delivery chamber can escape, (g) a sealing recess extends around the delivery chamber in at least one of the sealing surfaces (6, 7) forming the sealing join, and the sealing recess is filled with a sealing liquid, preferably a lubricant for the gas pump, at least when the gas pump is in operation, in order to seal off the delivery chamber on its outer side, such that sealing it off by means of an additional sealing ring can be dispensed with, or a sealing element which is arranged in the sealing recess is elastically press-fitted when the housing parts (1, 2) are joined and thus ensures the necessary seal at the sealing join, wherein the sealing element is elongated and/or secured orthogonally with respect to the sealing surface (6, 7) in order to prevent the sealing element from being able to be carried along by liquid flowing off out of the delivery chamber when the sealing join is widened.