气刹测试

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）”。

Air brakes are really three different braking systems: service brake, parking brake, and emergency brake. / 空气制动其实包含三套系统：行车制动、驻车制动与紧急制动。

When the low air pressure warning light and buzzer first come on, bring the vehicle to a safe stop right away, while you can still control the brakes. / 一旦低气压警报灯 / 蜂鸣器响起，应立即把车辆安全地停住，此时你仍能控制刹车。

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。

All trucks, truck tractors, and buses must be equipped with emergency brakes and parking brakes. They must be held on by mechanical force because air pressure can eventually leak away. Spring brakes are usually used to meet these needs. / 所有卡车、牵引车和客车都必须配备紧急制动和驻车制动。由于气压可能会泄漏，制动必须由机械力保持；通常使用弹簧制动来实现。

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。

When you push the brake pedal, air is let into each brake chamber. / 当你踩下制动踏板，空气会进入每个制动室。

Parking or emergency brakes must be held on by mechanical force because air pressure can eventually leak away. Spring brakes are usually used to meet these needs. When driving, powerful springs are held back by air pressure. / 驻车 / 紧急制动需要靠机械力保持，因为气压最终会泄漏；通常使用弹簧制动实现。行驶时，强力弹簧由气压“顶住”，因此不会介入。

The correct answer is expansion of the brake drums. 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：制动鼓膨胀。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。

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。

Pull forward at 5 mph, apply the service brake and stop. Check to see that the vehicle does not pull to either side and that it stops when brake is applied. / 以约 5 mph 前进，踩下行车制动并完全停住；检查车辆是否跑偏，以及踩下刹车时能否如预期停住。

Shut the engine off when you have enough air pressure so that the low-pressure warning signal is not on. Turn the electrical power on and step on and off the brake pedal to reduce air tank pressure. The low air pressure warning signal must come on before the pressure drops to less than 60 psi in the air tank. / 在低气压警报 未亮 时熄火，打开电源，反复踩放制动踏板让气压下降；在储气筒气压降到 60 psi 前，低气压警报必须亮起。

When driving, powerful springs are held back by air pressure. If the air pressure is removed, the springs put on the brakes. A leak in the air brake system, which causes all the air to be lost, will also cause the springs to put on the brakes. / 行驶中强力弹簧被气压 顶住 而不介入；若气压消失或泄漏，弹簧会 自动施加 制动。

Brakes can fade or fail from excessive heat caused by using them too much and not relying on the engine braking effect. Brake fade is also affected by adjustment. / 频繁使用制动、未依赖发动机制动会产生过多热量引起衰退；制动调整不当也会加剧衰退或导致失效。

You put on the brakes by pushing down the brake pedal. Pushing the pedal down harder applies more air pressure. Letting up on the brake pedal reduces the air pressure and releases the brakes. / 踩踏越重，施加到制动器的气压越大；松开踏板则减压并释放制动。

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。

A safety relief valve is installed in the first tank the air compressor pumps air to. The safety valve protects the tank and the rest of the system from too much pressure. The valve is usually set to open at 150 psi. If the safety valve releases air, something is wrong. Have the fault fixed by a mechanic. / 安全泄压阀装在压缩机首先充气的储气筒上，通常设定在 150 psi 打开，用以保护储气筒及系统免受过压；若阀门泄气，解释系统有故障，应检修。

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。

Compressed air usually has some water and some compressor oil in it, which is bad for the air brake system, the water can freeze in cold weather and cause brake failure. The water and oil tend to collect in the bottom of the air tank. Be sure that you drain the air tanks completely. / 压缩空气通常含有水和少量压缩机油，对空气制动系统不利。水在低温下会结冰导致制动失效；水和油易沉积在储气筒底部，应彻底放净。

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. / 陡坡下行应使用“缓压 / 点刹（snub）”法：施加足够的制动让车速明显下降；当速度降至比“安全速度”低约 5 mph 时松开刹车；当车速回到“安全速度”时重复。

Even if the low-pressure alarm is for the secondary system you need to stop at a safe location, park, and get the issue fixed. It is unsafe for the vehicle to remain in motion with a low air alarm. / 即便警报来自 副 系统，也必须在安全地点停车并修复后再行驶；在低气压警报亮起的情况下继续行驶不安全。

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。

ABS is a computerized system that keeps your wheels from locking up during hard brake applications. / ABS 是一套计算机控制系统，可在重度制动时防止车轮抱死。

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。