气刹测试

Brakes can fade or fail from excessive heat caused by using them too much and not relying on the engine braking effect, they are also affected by adjustment, and low air pressure. / 过度使用导致高温、调整不当、气压不足，都会引起制动衰退或失效；未充分利用发动机制动也会恶化问题。

Converter dollies built on or after March 1, 1998, are required to have antilock brakes. These dollies will have a yellow lamp on the left side of the dolly. / 1998 年 3 月 1 日及以后生产的转换拖架必须配备 ABS，并在左侧装有一个黄色指示灯。

To stop, the brake shoes and linings are pushed against the inside of the drum. This causes friction, which slows the vehicle. / 要让车辆停下，制动蹄 / 衬片会被压向制动鼓内侧，通过摩擦来减速。

You should brake in a way that will keep your vehicle in a straight line and allow you to turn if it becomes necessary. You can use the "controlled braking" method or the "stab braking" method. / 制动方式应保证车辆保持直线并且在必要时仍能转向。可使用“控制制动”或“点踩制动（stab braking）”。

A parking brake control in the cab allows the driver to let the air out of the spring brakes. This lets the springs put the brakes on. / 驾驶室内的驻车制动控制可放出弹簧制动回路的空气，使弹簧施加制动。

Stab braking means that you: apply your brakes all the way, and release brakes when wheels lock up. As soon as the wheels start rolling, apply the brakes fully again. / 点踩制动法：把刹车踩到底；车轮 一抱死 就松开；只要车轮 重新滚动 就再次把刹车踩到底。

Wedge brakes and disc brakes are less common than s-cam brakes. / 与楔式制动和盘式制动相比，S 形凸轮制动更常见。

Without ABS you still have normal brake functions. Drive and brake as you always have. / 即使没有 ABS，你仍然拥有正常的制动功能，按平时方式驾驶和制动即可，但应尽快检修 ABS。

The use of brakes on a long and / or steep downgrade is only a supplement to the braking effect of the engine. Once the vehicle is in the proper low gear you should only have to apply the brakes just hard enough to feel a definite slowdown. / 长 / 陡下坡时脚刹只是发动机制动的 补充 。预先选好低挡位，只需轻踩到 明显减速 即可。

In some vehicles a control handle on the dash board may be used to apply the spring brakes gradually. This is called a modulating valve. It is spring-loaded, so you have a feel for the braking action. The more you move the control lever, the harder the spring brakes come on. / 在一些车辆上，仪表台的控制手柄可逐步施加弹簧制动，称为调制阀。它有弹簧回馈，手感清晰；手柄推得越多，弹簧制动施加得越重。

A parking brake control in the cab allows the driver to let the air out of the spring brakes. This lets the springs put the brakes on. / 驾驶室内的驻车制动控制可让弹簧制动回路 排气 ，由弹簧施加制动。

Spring brakes are an important backup system: powerful springs that automatically apply the brakes if they sense that air pressure has been lost for some reason, such as a leak. They will also apply the brakes if the psi gets too low, although ideally, you should take control of your brakes before that happens. / 弹簧制动是重要的后备系统：当因泄漏等原因气压丢失或气压过低时，强力弹簧会自动施加制动。当然，理想情况下应在此之前由驾驶员主动控制并停车。

Any time you park use the parking brakes. Pull the parking brake control knob out to apply the parking brakes, push it in to release. / 每次停车都应使用驻车制动：拉出控制旋钮施加，按下释放。

You should brake in a way that will keep your vehicle in a straight line and allow you to turn if it becomes necessary. You can use the "controlled braking" method or the "stab braking" method. / 制动方式应保持车辆直线并能在必要时转向；可用控制制动或点踩制动。

Park on level ground and chock the wheels to prevent the vehicle from moving, release the parking brakes so you can move the slack adjusters, using gloves and pull hard on each slack adjuster that you can reach, and if a slack adjuster moves more than about one inch where the push rod attaches to it then adjustments are needed. / 在平地停车并垫好轮挡，释放驻车制动后，戴手套用力拉每个能触及的行程调节器；若推杆连接点位移超过约 1 英寸，就需要调整。

Snub braking method is used for steep downhill grades, in this method apply the brakes just hard enough to feel a definite slowdown. When your speed has been reduced to approximately five mph below your "safe" speed, release the brakes. When your speed has increased to your "safe" speed, repeat. / 陡坡下行采用“缓压 / 点刹（snub）”法：刹到比“安全速度” 低约 5 mph 时松开；当车速回到安全速度时再重复。

The warning light and buzzer should come on before the air pressure drops below 60 psi in either system. If this happens while driving, you should stop right away and safely park the vehicle. If one air system is very low on pressure, either the front or the rear brakes will not be operating fully. This means it will take you longer to stop. Bring the vehicle to a safe stop and have the air brakes system fixed. / 警报灯和蜂鸣应在任一系统低于 60 psi 前亮起 / 响起。行驶中发生这种情况，应立即停车并安全靠边。若一套系统压力很低，前轴或后轴的常用制动将不能完全工作，停车距离会变长；修复后再继续行驶。

If air pressure does not build up fast enough, your pressure may drop too low during driving, requiring an emergency stop. Don't drive until you get the problem fixed. / 若气压建立过慢，行驶中可能降至过低而不得不紧急停车。在修好之前不要上路。

With air brakes there is an added delay called Brake Lag. This is the time required for the brakes to work after the brake pedal is pushed. / 空气制动存在额外的 制动迟滞 （Brake Lag）：从踩下踏板到制动器真正起作用需要一定时间，因为空气要在管路中 流动 。

When the engine is at operating rpms, the pressure should build from 85 to 100 psi within 45 seconds in dual air systems. If the vehicle has larger than minimum air tanks, the buildup time can be longer and still be safe. / 在发动机工作转速下，双回路系统中的气压应在约 45 秒内由 85 上升到 100 psi。若储气筒大于最小规格，上升时间可能更长且仍属安全。

If the low air pressure warning comes on, stop and safely park your vehicle as soon as possible. / 低气压警报亮起，应尽快安全停车并靠边。

When main air pressure is lost, the spring brakes come on. Some vehicles have a separate air tank which can be used to release the spring brakes. This is so you can move the vehicle in an emergency. / 当主气压丢失时，弹簧制动会自动介入。有些车辆配有独立的储气筒，可用来释放弹簧制动，以便在紧急情况下把车辆挪动一小段距离。

The correct answer is your brakes may fail because of water freezing. Commercial drivers must manage speed and braking early, especially on downgrades, because heavy vehicles build heat quickly and need more distance to stop. / 正确答案是：水结冰可能导致制动失效。商业驾驶员必须提前控制速度和制动，尤其在下坡时，因为重型车辆制动会迅速积热，并且停车距离更长。

You should not drive faster to keep the tractor and trailer straight. When you drive a vehicle with ABS, you should brake as you always have. In other words: use only the braking force necessary to stop safely and stay in control; brake the same way regardless of whether you have ABS on the bus, tractor, the trailer, or both; as you slow down monitor your tractor and trailer and back off the brakes if it is safe to do so to stay in control. / 不应该为了让车身保持笔直而“开更快”。驾驶带 ABS 的车辆时：只用足以安全停车并保持可控的制动力；无论 ABS 在客车、牵引车、挂车或两者都有，制动方法都一样；减速时关注牵引车与挂车状态，安全时可稍松刹车保持可控。

Don't use the parking brakes if the brakes are very hot (from just having come down a steep grade), or if the brakes are very wet in freezing temperatures. If they are used while they are very hot, they can be damaged by the heat. If they are used in freezing temperatures when the brakes are very wet, they can freeze so the vehicle cannot move. Use wheel chocks instead. / 制动刚下长坡非常烫时，或在冰冻天气制动非常湿时，不要使用驻车制动；否则可能损坏或冻住。改用轮挡。