"The most comprehensive source for Automotive Tools & Equipment" All Vacuum Pump Oils Are NOT Created Equal Pumps using Robinair oil hold a deep vacuum longer! Change Your Vacuum Pump Oil Frequently Clean oil is important for peak vacuum pump performance. When the oil is contaminated, it reduces your pumps ability to remove moisture from a system. You should change the pump oil frequently, and especially in the following situations: You have just evacuated a system that you suspect was overly moisture-laden. You have just evacuated a system with a compressor burnout. The pump oil looks cloudy or milky. The pump will not pull to factory specifications when blanked off to an electronic thermistor vacuum gauge. Every 10 hours of operation. Premium High Vacuum Pump Oil The performance of your pump depends largely on the quality and purity of the pump oil. Robinair's oil is engineered to maintain maximum viscosity at high running temperatures and to improve cold weather starts. To keep the pump operating at peak efficiency, change the oil frequently. Moisture and other contaminants can quickly deteriorate the purity of the oil, thinning the oil and reducing the pump's ability to reach deep vacuum conditions. Thermally Stable Laboratory tests prove that Robinair oil is more thermally stable in comparison to other leading brands... which means it resists breaking down due to heat for a longer period of time. Lower Moisture Content Robinair oil has lower moisture content than other oils, thanks to our special packaging and handling procedures. Moisture degrades the oil's purity, thinning it and reducing the pump's ability to reach a deep vacuum. Related "Robinair" Product Information AC Vacuum Pumps - Index Page Full Product Listing - Index Page