A gas turbine engine includes a shroud ring, a vane ring, and a secondary flow assembly. The shroud ring extends around an associated turbine wheel and includes a carrier segment and a blade track segment comprising ceramic matrix composite materials. The blade track segment and the carrier segment defining a shroud cavity radially therebetween. The vane ring includes a heat shield comprising ceramic matrix composite materials that forms an outer platform, an inner platform, and an airfoil defining a heat shield cavity radially through the heat shield. The secondary flow assembly includes a recirculating flow circuit having a discharge tube and a vane pressurizing tube; and the secondary flow assembly is configured to cool the blade track segment. The flow circuit is further configured to pressurize the heat shield cavity thereby providing a seal against the gases from the primary gas path entering the heat shield cavity.