A leak test checks whether the sealed inside of a flexible endoscope is still sealed. The scope is pressurized with air, and a breach in the outer covering, a seal, or an internal channel lets that air escape. CDC/HICPAC guidance places the leak test after each use and before manual cleaning, because damage that lets fluid in can lead to inadequate disinfection and further damage to the scope.
A failed test is a finding, not a diagnosis. Where the leak is, and what has already happened inside the scope, decides what the repair involves. Good notes taken at the tester make the repair review faster and the quote more accurate.
This page is an inquiry checklist. It does not replace the manufacturer instructions for use (IFU), your reprocessing policy, or a repair assessment.
What the Test Is Telling You
Most departments use one of two methods, as the IFU for that scope allows:
- Wet (immersion) test. The pressurized scope is placed in water and watched for a steady stream of bubbles.
- Dry (pressure) test. A gauge or automated tester watches for a pressure drop without immersion.
Some departments run a dry test first and immerse the scope only if it passes. Published best-practice advice from a scope manufacturer stresses three points that also affect what you can report:
- The leak-test connector and the scope connector must be dry before they are joined, so water is not pushed into the scope.
- The scope must be fully pressurized before it goes under water.
- Angulate the tip and work the control knobs during the test. Small leaks in the bending section often show only under stress.
If bubbles come from a channel opening and it is unclear whether they are a true leak or trapped air, flushing that channel with water can help tell them apart.
What to Record at the Tester
Write these down before the scope is disconnected:
| Item | What to note |
|---|---|
| Scope | Manufacturer, model, and serial number from the label |
| Method | Wet or dry test, and the tester or reprocessor used |
| Location | Bending section, insertion tube, distal tip, control body, a channel opening, or the universal cord |
| Behavior | A steady stream or occasional bubbles; whether it appears only when the tip is angulated or a knob is turned |
| Pressure | For a dry test, whether pressure fell and roughly how fast |
| Visible signs | Cuts or swelling in the bending rubber, pinholes, cracks at the distal tip, or fluid inside the eyepiece or image |
| History | When the scope last passed, and anything since: a difficult case, a drop, a crush, or a reprocessing error |
A photo of the leak point, taken while the bubbles are visible, is more useful than a description alone. Photograph the device only. Keep patient information out of photos and notes.
What Not to Do While You Wait
- Do not keep reprocessing the scope as if it had passed. Follow the IFU and your facility procedure for a failed test.
- Do not try to seal the leak with tape or adhesive. It hides the leak point and can make the repair harder to assess.
- Do not open or dismantle the scope. That makes the review harder and may affect what can be repaired.
What Fluid Inside the Scope Changes
A leak caught at the first failed test is often a contained repair, such as the bending rubber or a seal. A scope that has gone through cleaning or disinfection with a leak may have fluid inside. Fluid can reach the angulation system, the light guide, the image bundle, or the video electronics.
That is why the history matters. Say whether the scope was immersed after the leak appeared, and whether the image, light, or angulation changed afterwards. This does not decide repairability by itself, but it changes what the review needs to check.
Sending the Request
A complete request names the scope, the test result, the leak location, and the history above, with photos. If several scopes failed, list each one with its own serial number and result.
ProbeBridge coordinates flexible endoscope repair with specialist partner workshops in China. We confirm whether the scope can be evaluated, and agree the assessment, price, and terms, before anything ships. Start from the flexible endoscope repair page, or request a review directly.
Sources
- CDC/HICPAC, Essential Elements of a Reprocessing Program for Flexible Endoscopes (2017).
- Olympus Infection Prevention, Leak Testing Best Practices: Why Technique Matters (2026).
- ANSI/AAMI ST91:2021, Flexible and semi-rigid endoscope processing in health care facilities.