2015-2017 WRX STI Brake Lines

Stainless steel brake lines replace the rubber flex hoses on your 2015-2017 WRX STI with PTFE-lined, braided-steel lines. The factory rubber hoses expand slightly under hard braking, creating a soft pedal; stainless lines eliminate that expansion for a firmer, more consistent pedal — especially noticeable on track or during repeated hard stops.

This is a feel and consistency upgrade, not a stopping-distance upgrade. If your pedal feels vague or changes through a session, lines plus fresh fluid are the fix. Pair them with high-temperature brake fluid — old or standard fluid boils long before the lines become the limiting factor.

Quality details: DOT-compliant lines with proper end fittings for the WRX STI chassis, abrasion-resistant outer coating to protect the braid, and correct length for your ride height. Cheap lines with poor fittings are a safety risk — this is not a place to bargain hunt.

Brake work involves the hydraulic system: bleed thoroughly after install and check for leaks before driving hard. Every line kit here is confirmed for the 2015-2017 WRX STI — filter by front/rear position.

While you are in there, it is the ideal time to flush the brake fluid — most WRX STI owners neglect it, and fresh high-temp fluid is the single biggest reliability improvement for repeated hard braking. Stainless lines, fresh fluid, and a proper bleed transform pedal feel for relatively little money.