Skip to main content


The breather system consists of an air separator assembly mounted to the inlet side of the turbocharger, along with an oil drain tube(s), check valve(s), required breather piping and mounting hardware.See Figure 35497 . ‪

1. Turbine Housing ‪

3. Air Separator Assembly ‪

2. Compressor Housing ‪

Typical Air Separator System

The system performs three functions: ‪

  • Collects the crankcase vapors normally emitted to atmosphere and separates particles of oil from the vapors. Any oil collected in this manner drains back to the crankcase, while the remaining fumes are mixed with the turbocharger air flow. This system virtually eliminates crankcase fumes from the engine room.
  • Filters the outside air entering the turbocharger. The oil-coated filter element removes dirt and salt particles from the incoming air.
  • Serves as an air silencer to reduce air induction noise.

Repair or Replacement of Air Separator Filter Element

Refer to OEM for repair procedures. ‪


Failure to clean the air separator filter and the vacuum regulator/limiter will affect the operation of the air separator and may cause reduced engine performance and/or engine damage caused by engine overheating. ‪

Refer to section , preventive maintenance for change intervals and cleaning and replacement procedures. ‪