When it comes time to add brake fluid to your brake system, you’ll do it at the master cylinder.

But it’s not as simple as topping off the reservoir and calling it a day.

There will usually be a “Max. Fill” line marked on the master cylinder, and it’s there for good reasons.

In today’s video, the brake brainiacs at Raybestos explain why you should be mindful of not overfilling your master cylinder, because it can lead problems such as:

  • Unwanted brake drag
  • Brake system overheating
  • Premature brake pad wear

It’s a good watch, even if you’re an experienced gearhead, as it delves into a bit of the hydraulic science that goes into automotive brake system design.