A fluid reservoir comprising: at least one first cavity and one second cavity in fluidic communication with each other and adapted to accommodate fluid, said fluid reservoir further being connected to a fluid-container system (7, 8, 9, 11, 22), a fluid consumer in fluidic communication with at least said second cavity, a pressurization system (1,2) adapted to generate a pressure, and a vacuum system (58, 59, 60) adapted to generate a pressure below ambient pressure, said fluid reservoir comprises an inlet port to a second conduit connected to said first cavity for connection of said fluid-container system (7, 8, 9, 11, 22) to said first cavity via a first hose, said fluid reservoir being designed so that either said pressurization system (1, 2) or said vacuum system (58, 59, 60) can be made to alternately affect the pressure in said first cavity, and said fluid reservoir being designed so that said pressurization system (1,2) can be made to affect the pressure in said second cavity, characterized in that said vacuum system (58, 59, 60) being designed to generates a pressure below ambient pressure in said first cavity, causing fluid from said fluid-container system (7, 8, 9, 11, 22) to flow into said first cavity, said pressurization system (1,2) being designed to causes fluid in said first cavity to flow into said second cavity and generates a feed of fluid to said fluid consumer, and a first check valve is disposed in a joint (12, 36, 37) between said fluid-container system (7, 8, 9, 11, 22) and said first cavity, preventing return flow of fluid to said fluid-container system (7, 8, 9, 11, 22) when said pressurization system (1,2) affects said pressure in said first cavity. at least one first cavity and one second cavity in fluidic communication with each other and adapted to accommodate fluid, said fluid reservoir further being connected to a fluid-container system (7, 8, 9, 11, 22), a fluid consumer in fluidic communication with at least said second cavity, a pressurization system (1,2) adapted to generate a pressure, and a vacuum system (58, 59, 60) adapted to generate a pressure below ambient pressure, said fluid reservoir comprises an inlet port to a second conduit connected to said first cavity for connection of said fluid-container system (7, 8, 9, 11, 22) to said first cavity via a first hose, said fluid reservoir being designed so that either said pressurization system (1, 2) or said vacuum system (58, 59, 60) can be made to alternately affect the pressure in said first cavity, and said fluid reservoir being designed so that said pressurization system (1,2) can be made to affect the pressure in said second cavity, characterized in that said vacuum system (58, 59, 60) being designed to generates a pressure below ambient pressure in said first cavity, causing fluid from said fluid-container system (7, 8, 9, 11, 22) to flow into said first cavity, said pressurization system (1,2) being designed to causes fluid in said first cavity to flow into said second cavity and generates a feed of fluid to said fluid consumer, and a first check valve is disposed in a joint (12, 36, 37) between said fluid-container system (7, 8, 9, 11, 22) and said first cavity, preventing return flow of fluid to said fluid-container system (7, 8, 9, 11, 22) when said pressurization system (1,2) affects said pressure in said first cavity.