Mostly the same as Palangi said.

After dumping out the liquid Oil you can also use Diesel Fuel or Solovent to clean the Mesh and inside the cannister.

If the Mesh area has dirt crusted up in it it might be needed to soak it over night. Blow out carefully with compressed Air if you have it.

Dirt and thick Oil will be at the bottom of the canister. If stiff use something wooden or plastic to scrape it out.

They still us Oil Bath Air Filters on the little Gen Sets that power the Refer units on refergerated container type Trucks.

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84 300D, 82 Volvo 244Gl Diesel