What size are the brake pipe nipples on 2001 model
 

I want to order them online but don't know size and type (supposedly there is more than one type of these things)

I'm quoting nipples for 2004 variants here so if you find your nipple part no is the same.
3/8-24x1.172. on Mopar cat no of 4126 879. (24 be threads per inch and 1.172 is pitch)
Got this from Bleed screw interchange where you get nipple size from your cat no.
Loads on Fleebay. Looks like its UNF thread. But you need the length. Stainless ones too.
Try a Motorfactors with the size. Or maybe Hal fords.

An internet Chrysler dealer quotes 2001 same part as for 2004. 4126879AB.

Thanks Goggs