By John Gunnell
They are called braided stainless steel brake lines or braided stainless steel brake hoses. Whatever you call them, they are flexible hoses designed to take the place of conventional rubber hoses in a hydraulic brake system.
Braided stainless steel brake lines were developed to improve brake system performance and effectiveness. They will also last much longer than flexible rubber hoses because they eliminate the brake hose expansion that affected rubber brake hoses.
Differences in the way that rubber hoses and braided stainless steel hoses are constructed accounts for their different expansion characteristics. Conventional brake hoses usually have a rubber inner hose wrapped in a braided fabric reinforcement braid. On top of this is an additional layer of outer sheathing that is also made of rubber.
Braided stainless steel hoses typically feature a generic polytetrafluoroethylene or Teflon inner hose wrapped in braided stainless steel wire. The stainless wire braid is what increases resistance to expansion from the pressure that builds up inside the inner hose. This improves the performance of the brake system because there's a more direct transfer of the driver's braking actions to the friction surfaces at the wheels that stop the vehicle.
Usually — but not always — the stainless steel braiding is coated or covered with a clear or colored material (such as polyvinyl chloride or PVC) to protect the wire and inner hose from the elements and chemicals and to help minimize abrasion. The coating also gives a better appearance.
Coated braided stainless steel hoses have the same basic make up as conventional rubber hoses in the sense that you have a rubber inner hose wrapped in a braid followed by an outer layer, but the stainless steel hoses provide substantially different — and most say better — braking performance.
For any user of stainless steel brake hoses, higher cost is required to purchase a set of hoses. They will generally cost from two-and-a-half to three times as much as conventional rubber hoses. Do, safety and better braking comes with a cost. Our set of three hoses cost just under $100 with shipping. For car collectors, a non-original appearance might be considered another drawback. If your car is going to be judged for originality, those shiny, thin braided stainless steel hoses are going to cost you points.
Braided stainless steel hoses are considerably thinner than conventional rubber hoses. This is because the outer layer of thick rubber used to protect regular hoses from road damage is no longer required. The thinness of the braided stainless steel hoses should not worry you, but it is a good idea to check that they are about the same length as the original hoses you're replacing. That way you know they are long enough for the application and will work without getting tangled on some suspension part when you turn the steering wheel.
The design of the new hoses may not exactly match the design of the old hoses. This is probably because the parts manufacturer isn't designing new parts for old cars. Someone has simply figured out the proper length hose to replace the hoses on your old car. But the new hoses may have differences such as a shorter or longer threaded nipple on one or both ends. The hoses we purchased from TSI Automotive were for a Triumph TR8. The original rubber hoses had one nipple that was shorter than the other, while the braided stainless steel hoses had the same length nipples on both end. The overall lengths were the same.
The installation of the new brake hoses was very straight forward and simple on the Triumph TR8, especially since we had all of the brake and many of the suspension parts already removed from the car. However, the old brake hoses were still on both sides of the car. We decided to do one side at a time, so the other could be used as a model to show us where each fitting goes. That way we knew that both sides would be put together properly.
Car hadn't been driven in years so it seemed like a good idea to replace the old rubber hose. Caliper end piece is tucked up to prevent brake fluid drips.
The TR7/TR8 braided stainless steel brake hoses kit came in plastic bag from TSI Automotive (www.tsimportedautomotive.com).