The original Dura Flush was HCFC-141b with about a 90 degree F boiling point.

The Dura II has about a 106 degree F boiling point and is about 50% HFC-4310me/HFC-365 (Dupont's replacement for the now regulated 141b) and about 50% t-DCE (trans,1,2-dichloroeth... Login to read more.