Operation CHARM: Car repair manuals for everyone.

Fluorescent Dye Detection




Fluorescent Dye Leak Detection










Fluorescent Dye Detection

NOTE: Ford Motor Company vehicles are produced with R-134a fluorescent dye installed in the refrigerant system from the factory. The location of leaks can be pinpointed by the bright yellow-green glow of the fluorescent dye under a UV lamp. Since more than one leak can exist, make sure to inspect each component, line and fitting in the refrigerant system for a leak.

NOTE: Use of dye-enhancing glasses or goggles greatly improves the detection of the dye under the UV lamp.

NOTE: Not all UV lamps will fluoresce the dye used in Ford vehicles. All Rotunda UV lamps are optimized to fluoresce the dye.

1. Check for leaks using a Rotunda-approved UV lamp and dye enhancing glasses.
- Inspect all components, lines and fittings of the refrigerant system.

2. After the leak(s) is repaired, remove any traces of fluorescent dye with a general purpose oil solvent.

3. Verify the repair by running the vehicle for a short period of time and rechecking the area of the leak with a Rotunda-approved UV lamp.