The catch that holds the lid shut compresses the gasket at a certain pressure. When that pressure drops the gasket no longer seats and the seal is lost while the lid still looks closed; days later it comes back as a temperature deviation in one container.
Less resistance than before when closing, a changed closing sound and a gasket mark fading in one area are signs of loosening. Place a thin paper strip between the gasket and the body, close the lid and pull the strip; where it slides out easily, the pressure has dropped. Test the four edges separately, but treat the result as a screen, not a seal test.
Read the paper-strip result this way first:
- Loose at one corner: the catch adjustment.
- Loose along one edge: the gasket is not seating.
- Loose everywhere: the gasket is worn out.
- Lid closes crooked: the hinge or the body.
Do not close the catch by force; adjust it only if the model's maintenance instructions allow it, and repeat the paper-strip test. If nothing changes, move on to the gasket or the hinge. Contact Aris Makina with the container ID, photographs and part code; record the finding, the maintenance done and the release decision in the work order.
