How To: Replace dual external air cleaners

Classically styled trucks often have dual air cleaners on either side of the cowl. These cleaners offer a larger space for the air filter cartridge than the under-hood cleaners on aerodynamically styled trucks.

However, they have so much capacity for dirt that the filter can deteriorate significantly before it’s clogged, so changing early is a good idea. If your air filter restriction gauge – dashboard mounted on this Peterbilt – is reading three-fourths of the way to the red line under maximum load and at maximum rpm, changing the cleaner is advisable.

Dave Brown, shop foreman at Hunter Keystone Peterbilt in Lancaster, Pa., ran us through the process.

Preparing for the job:

  • Turn off the engine and be vigilant throughout about clearing dust built up in or outside the housing, or dust that may fall from the cartridge into the intake piping.
  • All Peterbilt air cleaners have a bulb at the bottom for water and debris draining. Squeeze it – and make a practice of doing so every few days.
  • On this Pete 388, removing the cartridges required removing the mirrors first.

Doing the job

  1. Turn the top of the cleaner counterclockwise to bring the spring-loaded retaining washers in line with the holes at the ends of the mounting slots. Lift it off.
  2. Remove the cap nuts from the intake air screen. Remove the screen and the aluminum cartridge retainer. If the latter sticks to the rubber seal on the housing, use a rag to pull around the lip to loosen it.
  3. Grab the cartridge along the inner edge of the seal and pull up to remove it. If necessary, wiggle to loosen it.
  4. Inspect the intake air piping and clamps between the air cleaner and turbocharger for leaks, then insert the new cartridge. Press down to ensure a good seal. Install the retainer, pressing down to seal.
  5. Install the intake air screen, then the cap nuts that secure it, tightening in a crisscross manner to a low torque in several stages.
  6. Install the aluminum cap, positioning it so the attaching washers will slide through the holes. Turn it clockwise to lock into position.
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