A gas shield arrangement for a gas turbine engine includes a first gas shield that is arranged to cover an inlet of a gas flow path of the gas turbine engine and a second gas shield that is arranged to cover a first outlet of the gas flow path of the gas turbine engine. The gas shield arrangement further includes a reservoir that holds fluid and a pump that pumps the fluid from the reservoir to one of a first valve and a second valve and that returns at least some of the pumped fluid to the reservoir from the other of the first valve and the second valve.