When replacing brake pipes, use only double-walled steel pipes. The size of the tube is determined by its outer diameter.
If you are unable to obtain finished tubes, find suitable steel tubes and fittings similar to those you are going to replace. Using the old tube, determine the required length and cut off the appropriate section of the new tube, adding approximately 12-14 mm at the ends for rolling.
1. Install the fittings on the ends of the new tube and flare the connections.
2. Reshape the tube according to the old shape.
3. If you do not have the necessary equipment, you can take the tubes for expanding and bending to the service station.
4. When installing a new brake pipe, make sure there is at least 3/4 inch clearance between it and any moving parts.