A mechanical system comprising a sump and at least one component to be lubricated or cooled arranged in the sump, the mechanical system comprising a lubricating fluid system provided with a lubricating fluid and a tank arranged in the sump. The tank is a leaking tank and is situated above said at least one component to be lubricated or cooled, the lubricating fluid flowing out of the tank by force of gravity, so as to reach said at least one component to be lubricated or cooled. The lubricating fluid system has at least one lift flow generator connected by at least one filling line to the tank and to at least one suction point present in a bottom of the sump. The lift flow generator fills the tank with the lubricating fluid present in said bottom at least during a starting phase.

A lubrication system for a mechanical system, the lubrication system comprising a main tank, a reserve tank and a main lubrication circuit. The main lubrication circuit comprises, in particular, a pump drawing in the lubricating liquid from the main tank via a main suction point and a main suction pipe connecting the main suction point to the pump. The reserve tank is supplied with lubricating liquid either directly from the main tank or via the main lubrication circuit. The reserve tank is connected to the main suction pipe via an outlet pipe and the reserve tank is located above the main suction point so that the lubricating liquid flows through the outlet pipe to the main suction pipe by gravity.