Sealey Leak Detector Oil 500ml. Using leak detection oil allows the technician to pinpoint all manner of system leaks including the air intake, cooling, evaporation, fuel, exhaust and vacuum systems. It does not damage vehicle components during use. The leak detector oil can be poured directly into the smoke diagnostic tool. Model No. LDO50. This product is a diagnostic tool and is easy to use for VS868, VS869, VS870. Nett Weight: 0.47kg.