Oil filtration unit comprising: - a housing, which comprises a housing inlet adapted to receive contaminated oil from the surroundings and to release the contaminated oil to an inner opening of the housing, and a housing outlet adapted to release filtered oil to the surroundings, where the inner opening of the housing is defined by an inner bottom surface, an inner top surface, and at least one inner side surface, - an oil filter for filtering the contaminated oil, said oil filter being arranged inside the inner opening of the housing, where said oil filter comprises a filter inlet defined by an outer surface of the oil filter, an inner filter volume adapted to receive filtered oil, and a filter outlet inside said housing providing fluid communication between the inner filter volume and the housing outlet in order to release the filtered oil from the inner filter volume, and where said oil filter further has a top and a bottom end surface attached at opposing ends of said oil filter relative to the longitudinal axis of the oil filter, characterised in that - the top end surface of the oil filter comprises at least one aperture providing gas and/or liquid communication between the inner opening of the housing and the inner filter volume, - said top end surface further comprises a tube, and where a first open end of said tube is connected to said at least one aperture, and a second open end of said tube extends away from said top end surface, - where the second open end of said tube is located adjacent to the inner top surface of the housing, when the oil filter is arranged inside the inner opening of the housing. - a housing, which comprises a housing inlet adapted to receive contaminated oil from the surroundings and to release the contaminated oil to an inner opening of the housing, and a housing outlet adapted to release filtered oil to the surroundings, where the inner opening of the housing is defined by an inner bottom surface, an inner top surface, and at least one inner side surface, - an oil filter for filtering the contaminated oil, said oil filter being arranged inside the inner opening of the housing, where said oil filter comprises a filter inlet defined by an outer surface of the oil filter, an inner filter volume adapted to receive filtered oil, and a filter outlet inside said housing providing fluid communication between the inner filter volume and the housing outlet in order to release the filtered oil from the inner filter volume, and where said oil filter further has a top and a bottom end surface attached at opposing ends of said oil filter relative to the longitudinal axis of the oil filter, characterised in that - the top end surface of the oil filter comprises at least one aperture providing gas and/or liquid communication between the inner opening of the housing and the inner filter volume, - said top end surface further comprises a tube, and where a first open end of said tube is connected to said at least one aperture, and a second open end of said tube extends away from said top end surface, - where the second open end of said tube is located adjacent to the inner top surface of the housing, when the oil filter is arranged inside the inner opening of the housing.