If you routinely assemble flared tube fittings and have no problems with "leakers" then you can skip this tip. Many experienced mechanics have the feel for tightening these flare nuts properly and do not use a torque wrench.
                                   
                                   
                                    
                                   
                                   
                                    Many builders of homebuilts 
                                    do not have that experience 
                                    and creating reliable, leak-free connections is not an intuitive procedure. 
                                    Too loose
                                     and the connection will leak. 
                                    Too tight
                                     and the connection can leak and even crack the aluminum fittings. These are critical connections for fuel, brake, and oil cooler lines that we 
                                    cannot afford to have fail 
                                    on our aircraft!
                                   
                                   
                                    
                                   
                                   
                                    The 
                                    type of aluminum tube or flex hose
                                     used in the flare connection will determine the torque required - they are not all the same! This video will show you where to find the 
                                    source of torque values
                                     to use and the 
                                    procedure
                                     to tighten the nut using a torque wrench.