Product Information

Airwolf Air/Oil Separators

For over 25 yrs, Walker Engineering made THE best Air/Oil Separator money could buy. Unfortunately, in 1997, Walker was so busy supplying the OEM diesel & marine engine mfgs with AirSeps, they just didn't have time to build them for aviation and ceased production. Airwolf acquired all the rights and STCs from Walker Engineering and has expanded the elligibility listing to include all piston powered arcraft. If it burns avgas, then we have an air oil separator approved.NOW AVAILABLE The MiniAir Sep, an effective air oil seperator solution only with only a 3" diameter and 4" tall. Call to find out more.

What Makes the Airwolf AirSeps so darn good?


  • Mr. Walker spent 20 yrs refining his original AirSep which started out the size of a 1 gallon milk jug down to its present size
  • Walker discovered that if it was altered to make it any smaller, it would thereby defy the laws of physics, and it just won't do an effective job.


  • The Airwolf AirSep is almost 500% larger than the competition's heavily advertised separator that you can fit in the palm of your hand.
  • The reason? A well designed AirSep must force the air/oil stream to spend as much of time as possible inside the AirSep, otherwise oil residue just blows out the bottom onto the belly of the airplane. This takes time and space [volume].


  • The secret to the Airwolf AirSep, is that we used very hot air from the exhaust of a wet or dry vacuum pump. it does matter which one is on your aircraft, we are looking for a source of hot air. In the case of all electric aircraft with glass panel displays, we rob hot air off the upper cylinders to heat up the AirSep. This hot air is typically 250 - 275 F. As long as we keep the AirSep can above 212 F, then the water boiled off the sump as steam, stays as steam and passes right through the AirSep. Only the oil is coolesced. No water condeses in our can. In addition, we use a tiny amount of vacuum pump discharge air, to suck the oil out of the AirSep, and give it a little push to overcome crankcase pressure and return collected oil to the engine while the engine is running.
  • This above fact is what seperates the Airwolf AirSep from all other air/oil separators. Airwolf is the only AirSep the actually dries your engine out by removingharmful moisture. Best comment we have ever heard was at a Cirrus migration years ago in Duluth. One of the Cirrus factory mechanics saw our Airwolf jackets and said "Hey Airwolf, your AirSeps are a snow cone machine." We looked puzzled and asked him what he meant. He went on to say he was the mechanics who installed one of our AirSeps on a company SR22 to see how it perforned. He said it was a cold day in Duluth, [no we did not ask him how cold that actually was] and that when they ran the aircraft up on the ramp, the moisture coming out of the AirSep was freezing as soon as it hit the ramp, and starting building a snow cone from the bottom up. This was perfect validation to our statement that our AirSeps remove the water from the engine breather air and only recover the oil back into the engine.
  • Competitive systems are only gravity flow so no oil returns into the engine until the engine is completely shut off.
  • The out of business competitors tiny aluminum can, condensed all the moisture and stuck it back into the engine. Regardless of their marketing hype that their device magically seperated water from oil, the cold hard fact is everything that come out of the breather went back into the engine. So while their Air/Oil Separator might have been marginally effective at "keeping the oil off the belly of the aircraft", all the moisture [water] was returned back into the engine made it do far more harm, than good.


  • We took all the good from the original Walker AirSep and made them a lot better. Because we only supply AirSep for aircraft, we were able to concentrate our efforts to make the very best Air/Oil Separator available for aircraft today. We know what we are doing and very, very good at perfecting products. Remember this the next time you read an article from some blowhard aviation "expert" who know writes that "all air oil separators are bad". Nonsense! Some were, but over time they all have gone of business. A properly designed AirSep like our Airwolf, does no harm to the engine. Think of us more of an oil recovery system. The more the oil is tossed out the more we return it. Lets say you have an engine that has high compressions, yet you are seeing a lot of oil on the bottom of the aircraft. Should you replace very expensive cylinders when you are still making horsepower? We think not. What you have is oil getting by the lower scraper rings on the piston, and being tossed out the breather onto the aircraft belly. You have a cosmetic problem that we can deal with. We can capture this oil and return it right back to where it came from.


  • The Airwolf AirSeps are complete with EVERYTHING you need to install it onto the airplane. We not perfect and never going to be, and kit them as to what history has shown works right out of the box on the majority of the aircraft. In the event you want to exhange a pieces part out of the kit for something that will work better on your specific airplace, no problem. As long as it comes back brand new, with no scratches, dings, dents or damage, we will gladly exhange it for what you need.
  • The out of business competitors gave you nothing but a tiny aluminum tube.
  • The out of business competitors did not include hoses, clamps, brackets, doublers... NOTHING but what you saw pictured in a persons hand.
  • You ended up paying your mechanic a lot more than you initially thought, because he had to build all the needed parts you should have got [which Airwolf supplies with their kits] in the first place.


  • One system is large enough to clean both the engine breather oil and wet vacuum pumps discharge.