Review on Robinair 15600 CoolTech Vacuum Pump by Rick Marie

I have always valued Robinair for their air conditioning systems and I have this 15600 pump along with their gauge kit, RG6 recovery unit, refrigerant ID 134a, scale TIF and lots of fittings. I recommend the 15600 deep vacuum pump for car/truck air conditioning. With proper care, the pump will last for many, many years. It is very important to use Robinair premium high vacuum pump oil which will ensure the seal can be made to achieve a constant vacuum of 15 microns. Please note: All oils are hygroscopic, the oil retains moisture from evacuating the system. Learn how to use the gas ballast feature to minimize water contamination of the pump oil. This combination of oil and water forms hydrofluoric acid, which poisons a two-stage elliptical chamber that is being evacuated. If you don't change the oil after EVERY USE and don't add fresh oil, you will permanently damage the pump and you'll never get that low 15 micron preload again. When filling with oil, carefully follow the pump instructions. That means DO NOT FILL to the middle sight glass line at first! Only fill the reservoir to the BOTTOM of the sight glass. Run the pump for a few minutes and the oil level will rise closer to the center line as it heats up and expands. Then add a small amount of oil up to the center line while the pump is running. DO NOT OVERFILL or DO NOT FILL! Now the pump is ready to use, but FIRST let's check the pump's vacuum. If the pump can't hold a vacuum, you need to fix that first! If the vacuum pump cannot generate a vacuum of 15 microns within 5 minutes, there is a problem. The three nipple manifold has plastic caps with internal seals. These seals will leak under high vacuum and should be treated with a small amount of Nylog Blue according to the instructions for thinly coating each side of the cap rubbers. I am using a Thermal Engineering thermistor electronic vacuum gauge with the probe mounted on a 1/4 manifold fitting: Appion P/N VFL45L - 1/4" reversible 45 degree flare fitting. The vacuum sensor must always be ABOVE the to avoid oil contamination and permanent damage from kickback when the pump is shut off Close the isovalve that isolates the pump from your gauge set Start the pump and allow it to drop to 15 microns as shown on your thermistor vacuum gauge ..Turn off the pump and watch the vacuum hold after a few minutes Please note: It is almost impossible to determine the vacuum unless you have an electronic micrometer! A pressure gauge kit will not help! This is a very high quality vacuum pump and following the instructions will ensure it will meet design specifications for many years Mike - ASE Master Automobile Tech & ASE Master Medium/Heavy Truck Tech