Technical Paper
Fundamentals and Common Problems of Seal Integrity Robustness of Standardized Brake Tubing Threaded Connectors
2007-04-16
2007-01-0557
There currently are only two industry wide utilized designs of standardized threaded connector for brake tubing. The ISO design incorporates a “bubble” style of tube's end-form while the JASO/SAE design includes double inverted “funnel” tube's flare. Both designs are based on the arrangement of two conical (frustum) surfaces which have to be pressed against each other in order to provide sealing. Seal integrity robustness of those standardized connectors is not sufficient as some retorquing is usually required in the course of the assembly process in order to seal a number of them. Accordingly each plant must allocate resources for the associated detection and rework process as they strive for zero leaks in the field. Numerous investigations and root cause analyses reveal some fundamental shortcomings in their sealing capability. In order to achieve sealed state of the connector some self-adjustment and certain degree of sustained deformation of its components is expected.