You're jamming across the dirt about to carve a tight turn through a sandy berm or you're puttering through a busy school zone on the way to pick up your kid. These two scenarios would seem to have little in common, but we'd bet in both cases you're counting heavily on your brakes to do their job reliably. Speed and power is great, but when it's time to haul your vehicle back down to slow you'll want some dependable stopping power, and part of that system relies on your brake lines. After the addition of go-fast parts, the grand smile on your face will quickly turn to an expression of panic should you be missing the vital braking power needed to bring your vehicle back to a halt in a safe manner.
Factory stock brake lines (the flexible portions) are commonly made from rubber hose and have a long history of reliability under normal driving conditions on the road. In contrast, stainless braid lines consist of a Teflon inner tube surrounded by other protective layers, one of them being braided stainless mesh hose. The Teflon tube offers several advantages. It does not expand with pressure, is unaffected by high temperature, is compatible with all types of brake fluid, and resists deterioration with age. However, the Teflon is fairly fragile to outside contact with debris or rubbing on nearby surfaces. This is where the stainless braid and other protective layers come into play to encase the Teflon.
Whenever you lift your rig or you're building something custom, you may be in need of longer brake lines. Sometimes it's possible that a longer rubber line with the same style connectors is available from another OEM application to meet your custom need. However, most times, an aftermarket stainless braid line is the answer.
For off-road applications, the stainless lines offer the benefit of increased puncture protection when compared to a rubber line. In a situation where the line may encounter trail brush or flying rock and dirt, a stainless braid line will survive such abrasion better than a rubber line will. A side benefit to the stainless braid is that it helps support the Teflon tubing so that it doesn't swell under pressure like a rubber line, and can provide a firmer pedal action. This becomes even more helpful with lifts where hose length is added and would normally contribute to greater hose bulge.
Hose Connectors
All brake hoses are terminated with either threaded connector ends or banjo style ends to mate to another fitting or hardline, or to a brake caliper. There are two basic means by which the end connectors are secured and sealed to the hose. The first method essentially crimps the connector to the hose with a metal ring. The second method uses a two-part assembly where the hose is captured between an inside and outside fitting that are screwed together. The latter style is a type that can be done without sophisticated crimping machinery using bulk hose and fittings. However, this type of line is sometimes used on race vehicles and is not approved for highway use.
Are Stainless Lines D.O.T. Approved?
Indulge us a bit here and we'll explain. Flexible brake lines on road vehicles are governed by Federal Motor Vehicle Safety Standard 106 which specifies the construction and test requirements for hydraulic hose assemblies. Department of Transportation (D.O.T.) approved hoses can only use a fixed crimped or swaged end fitting. Secondly, an approved hose must meet a `whip' test where the hose is flexed back and forth while pressurized to determine if the hose and fitting combination can withstand repeated movement without failure. Some stainless brake lines have failed this criteria due to hose failure where the hose enters the hard metal fitting.
 This is a typical factory...  This is a typical factory brake line running to a rear caliper on a truck axle. Often a partial steel line merges onto a rubber hose. This combination works reasonably well with stock components. However, as you go with a lift and/or large tires, an upgrade may be beneficial, and necessary, to keep the line from stretching as the suspension droops. |  Here's an accident waiting...  Here's an accident waiting to happen. This owner lifted the rear of his truck but failed to lengthen the rear brake line. It's only a matter of time until this taut rubber brake line fatigues and ruptures, causing rapid failure of the rear brakes. |  Stainless brake lines can...  Stainless brake lines can come in a variety of quality levels, construction, and with an array of end connectors to assemble most any brake line configuration you may be building from scratch or renovating. We'll look at this in greater detail as we proceed. |
 The size and quality of connection...  The size and quality of connection crimps can vary by manufacturer as well. |  Another area to look at for...  Another area to look at for quality is at the mating flare inside the end fitting. Note the smoother finish on the hose at the left. A better flare finish will seal more reliably when the fitting is tightened on the mating flare nipple. |  This hose was built by Crown...  This hose was built by Crown Performance Products (www.crownperformance.com), a manufacturer of stainless braided lines. One unique feature about their hoses we looked at are the one-piece steel fittings used. In the case of this connector, the outer female compression fitting, an inner hose barb, and the outer crimp sleeve are all part of a single manufactured component, as opposed to multiple separate pieces combined to make the complete end. The one-piece construction makes these ends extremely durable and maybe the most reliable means of hose termination available. |
 Stainless lines can be constructed...  Stainless lines can be constructed with a wide array of end fittings from the basic -3AN female fitting to banjo fittings, or a tee fitting such as this that can be used on an axle housing to split the fluid to two lines running to the individual calipers. |  Are your stainless braid lines...  Are your stainless braid lines D.O.T. approved? Many are not. There are a number of test conditions a hose must meet to be "street legal". An approved hose must meet stringent crimp fitting requirements and hose flex durability. |  This line is marked as D.O.T....  This line is marked as D.O.T. approved. The hose has external vinyl protection over the stainless braid, a good protection against abrasion on the mesh. Also, you can see the added vinyl support layer adjacent to the swage ring at the fitting. |