Blog Car Care Advice How To Add Brake Fluid Safely (A Detailed Guide + 5 FAQs)
Car Care Advice

How To Add Brake Fluid Safely (A Detailed Guide + 5 FAQs)

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The braking system is a vital safety feature in your vehicle. It consists of several components, including the brake pedal, disc or drum brakes, and most importantly, the brake fluid— the system’s blood.

Without this hydraulic fluid, your brakes could immediately fail, so you should always keep an eye on the brake fluid level.

How do you do it?

In this article, we’ll explain how to add brake fluid properly, the signs of low brake fluid, and answer some FAQs!

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Let’s get started.

How to Add Brake Fluid (5 Easy Steps)

You should check and add brake fluid (if necessary) every month. You don’t have to wait for your brake warning lights or ABS light to come on before doing so.

Here’s what you’ll need to refill your brake fluid properly:

Note: Consult your owner’s manual to determine your vehicles brake fluid. Using the wrong fluid  type could damage the internal seals in the brake line and hydraulic components (brake calipers, master cylinder, etc.).

Now, let’s see how you can check and add brake fluid on your own:

Step 1: Park Your Vehicle on a Flat Surface and Turn Off Your Engine

Park your vehicle on a flat surface and activate your parking brake to prevent it from free-rolling

For manual transmission cars, put the vehicle in first gear before applying the parking brake. Meanwhile, if your vehicle has ABS brakes, you’ll need to depress the brake pedal 30 times. This helps to push out any remaining fluid from the ABS channels.

And if you’ve just driven the vehicle, let the engine cool off first before continuing because you can burn by accidentally touching hot engine components. ONLY lift the hood once it’s cool to the touch.

Step 2: Check the Fluid Level

Next, you’ll need to locate your car’s brake fluid reservoir. It’s normally located inside the engine compartment on the driver’s side. But if you can’t find it, please refer to the car owner’s manual.

Once you’ve found the reservoir, observe the brake fluid level. The brake reservoir in newer vehicles are usually translucent and have “Maximum” and “Minimum” lines on the outside. You can easily check the fluid level without opening the brake fluid reservoir cap.

If it’s slightly below the “Maximum” line, then it’s alright, but if the level is closer to the “Minimum” line, you’ll need to refill it. Another thing to note is the color of the fluid. To do so, you’ll need to open the reservoir cap.

New brake fluid is clear with a yellowish tint and turns dark yellow or amber over time. Meanwhile, old brake fluid is typically very dark and might have debris in it.

Note: Proceed only if the fluid is low and isn’t contaminated or discolored. If the brake fluid is brown or black and has debris floating in it — it’s high time for you to schedule a brake fluid flush.

Also, if you suspect that your low brake fluid level is caused by leaks, please contact your mechanic immediately.

Step 3: Refill Your Master Cylinder With Fresh Brake Fluid

Use a funnel to pour the new brake fluid into the reservoir until the fluid level reaches just below the “Maximum” line, or at least ⅔ or ¾ of the brake fluid reservoir.

Be careful when pouring the fluid, as brake liquid is highly caustic and can corrode engine parts, body paint and burn your skin. Remember to immediately wash the funnel with soap and water once done, and don’t reuse it for other purposes.

Step 4: Replace Your Reservoir Cap

Now that your reservoir is full, simply put the brake fluid reservoir cap back on the same way you removed it. Screw it back tightly to prevent moisture and air from entering the reservoir. This prevents the fluid from deteriorating.

Also, be sure to inspect the master cylinder for leaks and spillage. If you see a brake fluid leak, get your car towed to the nearest workshop or call a mobile mechanic.

Step 5: Pump Your Brakes

Once all that’s done, don’t forget to pump your brakes. 

This helps to push the newly added fluid into the brake lines. Essentially you’re priming the brakes by creating hydraulic pressure inside the brake lines with the fresh fluid.

You’ll need to pump your brakes about 30 times and stop when you feel the pedal engage.

Well, now you know the proper and safe way to add brake fluid. 
But is there another way to know you’re running out of hydraulic fluid without accessing the engine compartment? 

Let’s see how you can spot it.

Signs of Low Brake Fluid

There are several indicators of a low brake fluid level that you should watch out for, especially when on the road. 

These signs include and aren’t limited to:

If you experience any of the above, it’s best to stop at the nearest parking spot and inspect your brake fluid. Better yet, you should contact your trusted mechanic to get it checked out.

Now, time for some FAQs!

5 FAQs About the Brake Fluid

Here are the answers to some commonly asked questions about brake fluid:

1. Can I Drive With Low Brake Fluid?

Although driving with a low brake fluid level isn’t recommended, your vehicle will still run. If the fluid isn’t fully depleted, you can still drive your car to the nearest workshop or run simple errands.

But what happens when you do run out of brake fluid?
There’s only one way for your car to completely run out of brake fluid: a massive brake system leak (damaged pistons, brake line, hose inner lining, etc.)

If you continue to drive with a dry master cylinder, you’ll risk damaging the braking system and could end up with complete brake failure

Think of it this way; the brake fluid is like the blood of the braking system. Without it, your brake system is rendered useless.

2. How Does the Brake System Work?

The brake system is a series of tubes (brake lines) that connect the brake pedal to the brake components (brake pad, brake calipers, etc.) It slows down and stops a moving vehicle by converting its kinetic energy into heat energy (friction).

When your vehicle moves, the wheels produce kinetic energy. Pressing the brake pedal causes the master cylinder piston to be pushed inwards, creating hydraulic pressure in the brake line. 

The pressure is applied throughout the braking system, forcing the brake fluid to the brake caliper (for disc brakes) on each wheel. The pressure in the liquid activates the caliper to squeeze brake pads against the moving rotor which causes the wheels to stop moving.

3. Can Brake Fluid Expire?

Yes, brake fluid can expire.

This is because brake fluid is hygroscopic, meaning that it absorbs moisture, which reduces its performance and could corrode the internal brake parts. With that said, never leave a bottle of brake fluid open for too long.

4. Is Brake Bleeding Necessary After Adding Brake Fluid?

No, you don’t need to bleed your brakes if you’re only inspecting and refilling the reservoir. 

Brake bleeding is only needed if you’re emptying the old fluid in the system and replacing it with fresh fluid. Plus, it’s a pretty tedious task— you’ll need to get a brake bleeder, strip the wheels off to expose the wheel hub, and continuously monitor the fluid reservoir.

5. When Should I Replace My Brake Fluid?

Different manufacturers recommend different brake fluid replacement schedules, so it’s best to refer to your owner’s manual for the exact dates.

However, the basic rule of thumb is to get a brake fluid change every two years or 30,000 miles, regardless of the condition and brake fluid level. This ensures that your brake system stays in top condition.

Brake fluid should be replaced often because it decays over time, meaning its chemical properties will also change. It ends up with a lower boiling point, which causes it to heat up faster, making your brakes less effective when you press on them.

Wrapping Up

Caring for your brake system is fairly easy. Just make sure you check and refill the brake fluid now and then. If you follow our guide, adding brake fluid to your vehicle would be a cinch. 

However, if you suspect there’s something wrong with the brakes, like a brake fluid leak, or you need to change worn brake pads, it’s better to leave it to the pros — like AutoNation Mobile Service!

AutoNation Mobile Service is a mobile automotive repair service available 7-days a week. Our trained mechanics can diagnose and repair any automotive issue you may have.

Contact us today if you need a brake fluid flush or any brake-related service, and we’ll send our best technicians out in a jiffy!