A radiator funnel assembly facilitates filling refrigerant liquids in different radiators. The assembly provides various sizes and types of adapters and caps, with each adapter and cap having a unique identifier to facilitate assemblage and indicate a matching radiator fill opening. The assembly includes a funnel configured to receive a radiator fluid and carries the radiator fluid through a spout. Multiple conduits detachably attach in series to the spout. Multiple adapters receive the conduits and engage a specific radiator fill opening. Each adapter has a unique identifier that enables identification of the connecting conduit, and also identifies the specific type of radiator fill opening that is operable with the adapter. Multiple caps fasten the adapters to the radiator opening. Each cap has a unique identifier to identify and match to the appropriate adapter. This is useful for matching the adapter and cap to different types of radiators.