Procedure notes
When you hit the brake pedal in your 2009 BMW 135i it pumps brake fluid down to your brakes which increases the pressure to make your car slow down. If you don't have enough brake fluid in the brake fluid reservoir, air can get in your brake lines and your 135i won't stop properly. The video above shows you how to add brake fluid to your BMW 135i. If you are adding brake fluid to your 135i on a regular basis, you should check for leaks (we have a video for this too!) As with most fluids in your engine, brake fluid can cause serious harm if you get it in your eyes, so be sure to wear safety glasses and gloves. Brake fluid will also make your paint peel off if you spill it on your 135i, so be careful not to spill it.
When adding fluid to your 135i, it is important to check your owners manual for the correct type to add - it likely be either DOT 3, DOT 4 or DOT 5, also known as silicone brake fluid. Do not shake the fluid before pouring it in your vehicle - the air bubbles will foul up your brake lines. Be sure to discard bottles of brake fluid that are over a year old - brake fluid sucks the moisture out of the air and the water vapor in the fluid can rust out your brake lines quickly. Brake fluid breaks down with use and should be changed every 2 years in your BMW 135i or whenever it looks dark in color - this will make the internal brake components last longer.
查看中文对照 · Chinese translation
当你踩下2009BMW135i的刹车踏板时，制动液会被泵送到刹车系统，从而增加压力，使车辆减速。 如果制动液储液罐中的制动液不足，空气会进入制动管路，导致您的135i无法正常制动。 上面的视频展示了如何为您的 宝马 135i 添加制动液。 如果你定期为 135i 添加制动液，应检查是否存在泄漏（我们还有一段相关视频！）。就像发动机中的其他液体一样，制动液如果进入眼睛，可能会造成严重伤害，因此请务必佩戴安全眼镜和手套。 如果在135i上洒了制动液，也会导致漆面脱落，因此要小心不要洒出。
在为您的 135i 添加液体时，务必查阅用户手册以确认应添加的正确类型——通常为 DOT 3、DOT 4 或 DOT 5，也称为硅基制动液。 将制动液加入车辆前不要摇晃容器，产生的气泡会影响制动管路正常工作。 请务必丢弃使用超过一年的制动液瓶——制动液会从空气中吸收水分，液体中的水蒸气会迅速导致制动管路生锈。 制动液在使用过程中会分解，建议每 2 年在您的 宝马 135i 中更换一次，或者当其颜色变深时立即更换——这将有助于延长刹车内部部件的使用寿命。