Do I need to drain the entire cooling system before installation?

Yes. Disconnect the battery, let the engine cool completely, then open the drain petcock at the radiator base and catch coolant in a pan. Have fresh coolant on hand before you start — you'll lose the system charge during removal and reinstall.

Will this radiator work if my vehicle originally had an oil cooler attached?

No. This radiator is engineered specifically for 2.0L applications without oil cooling integration. If your Traverse came from the factory with an oil cooler, you'll need the model that includes those ports.

Are hoses and clamps included, or do I need to reuse my old ones?

Radiator assembly only — no hoses or clamps included. Your factory hoses can be reused if they're in good condition; inspect them for splits or soft spots before reconnecting. New hose kits are available separately if needed.