A device for storing fluid, of a transmission hydraulic system, having at least one storage chamber that is defined by a housing and a delimiting device, which can be connected with the hydraulic system. The volume of the chamber depends on operation of the delimiting device and/or the housing. The delimiting device and/or housing can be set such that the storage chamber has a defined volume, in opposition to a restoring effort of the housing and/or delimiting device, starting from an operating condition which differs from the operating condition equivalent to the minimum volume of the storage chamber toward their operating condition equivalent to the minimum storage chamber volume. When the holding device is actuated, the operating conditions of the delimiting device and/or the housing assembly vary between operating conditions in which the storage chamber volume is either a maximum or corresponds to the defined storage chamber volume.