发动机点火，然后踩下制动踏板并松手刹。

Start the engine, then press the brake pedal and release the parking brake.

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为保证车辆的安全运行，在气压制动系统中施加安全保护开关，控制发动机的点火电路(汽油机)或熄火电磁阀电路(柴油机)，可实现低气压时的自动保护。

The safety switch controlling the ignition circuit in gas engine and flameout magnetic valve in diesel engine is used in air brake system to realize the automatic protect.

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