RAIN/LIGHT SENSOR (RLS): OIL LEAKAGE FROM GEL PAD. ??Oil leaking from the Rain/Light Sensor (RLS). Note: This oil serves as a separation medium between the RLS mounting gel pad and the windscreen. The oil ensures damage free disassembly in case of repair. CAUSE The oil that serves as the separation medium of the Rain/Light Sensor (RLS) gel pad and the windscreen leaks out. Expose the Rain/Light Sensor (RLS) and properly clean the area of all oily residue. Note: The separating oil usually leaks only once from the pad at the RLS. Due to the small oil quantity in the gel pad, additional oil leakage is not plausible. Leaking oil does not impair the function of the RLS.