Abstract: A radiator funnel and adapter to prevent spillage comprises a funnel having a fluid receiving body and a spout through which fluid is dispensed; an adapter having a tubular member, a sealing flange, a flexible seal member, and a cap abutment member; a cap having a hole for receiving the top end of the tubular member and the spout which is engageably and sealingly inserted in the tubular member; and a stopper means having a stem, a plug portion at one end of the stem, and a handle at the other end to plug the bore through the spout. The adapter fits in the fill opening of the radiator and the cap fastens over the fill opening of the radiator and urges the flexible seal member and the sealing flange against the recessed ledge in the fill opening to substantially provide a seal between the adapter and the fill opening so that as fluid is poured into the radiator, the fluid won't spill out of radiator as it commonly bubbles up through the fill opening of the radiator.