To improve braking, especially in track duties, I recently upgraded my rotors to lighter, better ventilated Girodisc two-piece units that you can read about in my last post. While I had the brakes apart anyway, I opted to install 034 Motorsport stainless steel lines and flush the fluid out and replace with something rated for higher temps. Together, the new lines and better fluid are the final missing piece to get my brakes up to the challenge of track duty, and also provide a little extra assurance for street use too. The stainless steel brake lines from 034 Motorsport are DOT compliant, easy to install, well built, and just $120. For me, it’s a no brainer to buy these and enjoy the extra peace of mind from having more protection and more consistent pedal feel, especially if you need to change your brake fluid anyway. Read on to learn a little more about the advantages of stainless steel brake lines, as well as what fluid I chose for my TTRS.
Advantages of Stainless Steel Brake Lines
When hot brake fluid passes through your brake lines the heat expands the OEM rubber brake lines, which leads to a less consistent pedal feel. Generally with most factory brake systems at the end of a track day (or if you’re just romping on it in public streets), once the brakes get too hot your pedal will go soft and eventually go out – this is a result of the fluid getting too hot (as pedal gets soft) and then eventually boiling over (pedal goes out completely). Upgrading to brake fluid rated for higher temps will help with the latter (boiling over), but ideally you should upgrade your lines to handle the higher temps, too. This is why most aftermarket Big Brake Kits (BBKs) come with stainless steel lines. Additional benefits include protection from road/track debris being flung up at the lines, and many manufacturers suggest “looks” as an advantage, but I can’t ever imagine a scenario where someone would come up to you and say “hey, those are some sick looking brake lines, bro!” Regardless, if you have a lot of people checking out your brake lines at car shows, then perhaps this is another reason to consider the mod 😉
Brake Fluid Choice: Motul RBF600
While you’re replacing the lines, you’ll have to replace the fluid anyway – so perfect time to upgrade, if you haven’t already. The prevailing consensus on the forums is that Castrol SPF or RBF660 are the favorites for hardcore track junkies on the 8J TTRS platform, but I chose Motul RBF600 for my needs. The “600” in RBF600 means it is rated for ~600 degrees, which is pretty damn hot. The RBF660 gets you an additional few degrees of heat tolerance, which is unlikely for most users unless they’re serious drivers capable (and ballsy!) enough to push their cars to the limits…but comes at an additional cost, and requires more frequent changing/bleeding of the system. Motul actually suggests both RBF600 and 660 are intended for track use only and need more frequent bleeding, but overall RBF600 is more suitable for a daily driver and occasional track use. I only track 1-2 weekends a year, so I can live with having 60 degrees lower boiling point in exchange for a little more low maintenance of a fluid…worst case scenario, I can back off a little on my last few laps when my concentration (and tires) are at the end of their limits too.
Installation is easy, with just one line per side. Bleed the old fluid first, then remove the old lines and replace with the new lines using a wrench. Add new fluid and then bleed the system to get all of the air bubbles out. The bleeding of air bubbles is the only hard part, but no harder than if you had rubber/OE brake lines. If you’re only doing lines and fluid, the total job should take about an hour. You won’t notice a huge difference after installing, so if your brake pedal is soft that means you still have some air bubbles to work out of the system.