Brake Fittings & Adapters
For switching from one thread to another, branching a line or rerouting it. It is the part people forget to order, leaving the car immobilized for a week.
Concave or convex: the number one cause of leaks
A brake fitting seals through a conical seat, not through the thread. A convex cone must fit into a concave seat. Two convex seats screwed against each other will leak regardless of tightening torque - and tightening further will only damage both parts.
Common threads
M10x1.0 on most Japanese cars, M10x1.25 on some European cars, and 3/8" UNF on Anglo-American racing equipment (Wilwood, AP Racing). A hydraulic handbrake often combines all three: include the adapters when placing your order.
3-way tees
They split the rear line to the two calipers. Check the seat type at each of the three outlets, as they are not always identical.
