An automotive inverted flare hydraulic system is actually a one shot deal. It's not designed to take apart and re-use. A properly formed double flare on a steel tube should not be crushed completely flat as many people do with the clamp type flaring tools. The double flare should have a little give or crush left in it until it is tighten down in its final resting place. That way it conforms to the shape of the inverted flare in the brass fitting. At the same time the inverted flare in the brass fitting gets crushed a little bit also since it is softer then the steel line. After the joint is tight you have a unique matched seat until you disturb it. When you break the joint and try to reseat it, sometimes if you luck out there is still enough give in the brass inverted flare to form a seal but quite often there is not and you will have a leak.

When you break a hydraulic brake line open you create a domino effect which ends only when you terminate at a pipe thread or a flat seal with a copper washer. (Those copper washers are also a one shot deal unless you anneal them and remove the grooves.) In other words, you are way ahead of the game if you replace all the fittings and start with fresh double flared tubing.

With the steel line into the steel master cylinder your can usually get away with a couple shots before the line is crushed so much that it will not conform to the inverted flare in the master cylinder. This is also true in the case of the bleeders, after numerous bleeding sessions the bleeder screw will become work hardened and your better off replacing then, they are quite inexpensive.

Denny Graham
Sandwich, IL

Denny G
Sandwich, IL