i have a CAT 326-1643 fuel/ water separator dose any one know what machine they are for or go to
Call your local Caterpillar Dealer and ask the parts department what machines it will fit.
These are cross reference lookups. By no means exhaustive but it will give you some idea.... https://catalog.cumminsfiltration.com/catalog/CatalogSearch.do?partNumber_PartDeatils=FS20007 http://www.nfhconnect.com/Lookup/PartApplications?Part=3607
The 326-1643 is a pretty generic primary fuel filter/water separator that fits most of the newer Cat machines. It replaced th washable screen that used to be the norm in older equipment. The list of models that use it must be as long as your arm.