Freezer door allowing more frost build-up than normal

My husband took off the old gasket and replaced it with the new one. The old gasket was split in several places, and actually, since the freezer is about 27 years old, I didn't think we could find a gasket at all. I'm still not sure that it is sealing as it should since I don't hear the sound that indicated pressurizing. During storage and/or shipping, the gasket had developed a kink in it. I did lay it out on the floor in hopes the kink would straighten out some, which it sort of did. We plan to do just a little more adjusting to the hinge in hope that finishes the problem.