Recurring cooling loss traced to hidden Schrader valve leak

What we found

When the same problem repeats, the focus shifts to finding the leak source. We narrowed the circuit and checked the small service-port points that are often overlooked.

• Repeat cooling-loss history matched a slow leak pattern
• Wider circuit checks did not explain the repeat cycle
• Leak signs appeared at the service-port valve core area
• The leak path was small but consistent

The refrigerant was escaping at the service-port valve core. The leak was small — easy to miss during standard checks. But it was enough to drain cooling over a few months. Each top-up improved things for a while, but the leak path stayed open.

What we did

The leak is at the valve core, not the coil or compressor. Repairing this small component and confirming the system holds pressure before recharging is all that is needed. The repeat top-up cycle ends once the valve core is sealed.

After the valve-core leak path was corrected and the system was rechecked, cooling stabilized. The repeat top-up cycle stopped.

What we learned

Why the same top-up keeps failing — and how to find the hidden leak.

• A leak at the service-port valve core is small and easy to miss during standard checks, but it steadily drains pressure over months — enough to cause the same top-up cycle repeatedly.
• Each top-up works because pressure is restored, but the leak path stays open. The gas escapes again through the same point, and the cooling fades on the same schedule.
• Focused checks around the service port — separate from the wider circuit — are needed to catch a valve-core leak that wider inspections can overlook.