A lubrication system of a gas turbine engine includes a lubricant reservoir with a housing having a volume of oil located therein. A reservoir passage extends through the housing. One or more side passages extend from the reservoir passage and are configured to selectably fill or drain the volume of oil. An output passage is separate and distinct from the reservoir passage, and a separator wall extends into the interior of the housing from the first housing wall toward the second housing wall and between the reservoir passage and the output passage. When the lubricant reservoir is in a first orientation, the lubricant reservoir is filled via oil flowed through the reservoir passage from the first housing end, and when operated in a negative G orientation, the lubricant reservoir is drained via oil flowed through the reservoir passage and out of the second housing end.