servicing fuel preheater assy. what retains fuel preheater inside prefilter?
my prefilter is still in the truck and i am having problems trying to get it loose and i cant see what size or shape is inside the nipple.

thanks
mel

 

There is an allan top bolt in the center
Service instructions> http://dodgeram.org/tech/dsl/filter/pre-filt_clean.htm

 

thanks Infidel (Bill)

now i 'll update my post for others
it is a 5/16 allen wrench required to remove preheater from prefilter assy