[DelmarRey]

Don''t know how long you''ve owned you vessel But, It could be possible that someone modified the filter to make it work and then never replaced it.
Check your Westerbeke manual or go to your local Westerbeke dealer and get their version of the filter. Then you can go to auto parts dealers to get the interchange equivalent for that filter. Maybe not! Some diesels run very high pressures and regular automotive filters won''t stand up to the stress.
The PH8A has been around for many years and don''t understand why a new one would be differant.

Here is the West''r site:
http://www.westerbeke.com/