1987 Westerbeke 10-2 Diesel air filter ??????

[Chuck Powell]

My 1987 O'Day 272LE has a Westerbeke 10/2 diesel. As we all know, a diesel needs clean fuel, compression and clean air. The info provided in the Westerbeke manual shows an air pump on one of its diagram. What is the air pump referring to, and is there an air filter to be replaced?
Your response will be appreciated.

 

[Hydro Therapy]

My boat has a 94 W 10/2. It does not have an air filter. I’m not familiar with the air pump you mention.