Brake Line Tools

Brake line tools let you make and repair brake lines yourself, whether rigid pipes or braided hoses with reusable fittings. The range includes a flare tool for rigid lines, a double-ended mandrel for AN-3 and AN-4 braided hose, and a further brake line tool.

A rigid brake line seals where its flared end is pressed onto a seat by the tube nut, so the flare must be square, concentric and free of cracks. Flare styles differ: double (inverted) flares and bubble flares are both common on brake systems, and a fitting seals only with the style it was made for.

Reusable hose ends seal by clamping the hose’s PTFE liner between the fitting and an olive, so the liner must be cut square and undamaged. The mandrel has an AN-3 connection on one end and AN-4 on the other, the two usual brake hose sizes in motorsport.

Before you start, check two things:

• Flare style: confirm that the tool forms the flare your fittings need. Cut the pipe square and deburr it first, or the flare may split.
• Hose size: use the mandrel end that matches your hose, AN-3 or AN-4, when assembling reusable fittings, banjo eyes or hose ends.

Brake lines are safety-critical. Route lines clear of heat, sharp edges and moving parts, with enough slack for full steering lock and full suspension droop. Bleed the whole system, following the bleeding order the car maker gives. Then check each new joint under firm pedal pressure before driving, and look for weeping at every fitting after the first runs.