| 摘要 |
<p>The hand brake lever for the towing vehicle and trailer has two main valves. One couples the hold-off brakes to the air pressure, for releasing the brakes and the other vents the brakes for parking control. A third valve is included, which operates only on the towing unit brakes. The third valve is operated in an intermediate setting and allows the driver to test the towing vehicle brakes without applying the trailer brakes. This enables him to ensure that the brakes are functioning before uncoupling the trailer.</p> |
