摘要 |
<p>A pneumatically-operated braking system for a tractor-trailer combination incorporates a trailer control valve (4) for providing braking pressure for the trailer. The control valve (4) is adapted to be actuated by a pressure differential acting across it to limit the flow of air in the supply line (2) when a leak is present in the trailer control line (12), and the pressure differential is generated between the pressure in the supply line (2) and pressure supply from another independent source (1).</p> |