How Much Brake Fluid Do I Need: Change & Flush?

Maintaining your car brake system is important to keeping you and your family safe on the road. The brake system is responsible for stopping your car when you press the brake pedal, so it’s essential to ensure it’s in good working order.

But how much brake fluid does a car take?

It’s a must for brake fluid to be filled to an optimal level when flushing or adding the brake fluid. Today’s cars require about one quart or 32 ounces of brake fluid.

What is Brake Fluid and its Types?

Brake fluid is a type of hydraulic fluid used in brake systems. Its primary purpose is to transfer force from the brake pedal to the brakes.

Brake fluid is typically made from a mix of glycols and other chemicals and can be either DOT 3, DOT 4, or DOT 5 rated. DOT 3 and DOT 4 fluids are compatible with most brake systems, but DOT 5 is not always compatible. It is important to check your vehicle’s owner’s manual to see what type of fluid is recommended.

Wet Boiling Point Dry Boiling Point
DOT 3 140°C/284°F 205°C/401°F
DOT 4 155°C/311°F 230°C/446°F
DOT 5 180°C/356°F 260°C/500°F
DOT 5.1 180°C/356°F 260°C/500°F



DOT 3 braking fluid is a polyethylene glycol-based fluid formulated to tolerate extremely low temperatures without solidifying and hot temperatures without boiling. The usual boiling point of DOT 3 braking fluid is about 250 degrees Celsius. It often has a golden to amber-yellow color and a faint glycol odor. The brake fluid is partially soluble in water; nonetheless, mixing water with the product lowers the fluid’s quality.


DOT 4 Braking FLUID is an ultra-modern, quality brake fluid of extremely high quality. The fluid has a high wet boiling point and a substantial safety reserve from vapor lock.

DOT 4 BRAKE FLUID is perfect for drum brakes and hydraulic disc brakes on cars, motorcycles, commercial vehicles, and machinery. DOT 4 is gaining popularity because of the increased usage of traction control and anti-lock braking systems, all of which benefit from DOT 4 fluid’s reduced viscosity.


The silicone-based brake fluid DOT 5 is not compatible with ABS systems. In addition, DOT 5 should not be mixed with other brake fluids; unlike other brake fluids, it doesn’t degrade the paintwork.

What Are The Signs Of Low Brake Fluid?

There are a few signs that may indicate low brake fluid levels. The first and most obvious sign is the brake pedal itself. If the pedal feels “spongy” or “soft,” it could indicate insufficient brake fluid in the system. Additionally, if the pedal has to be pushed further down than usual to engage the brakes, this could also be a sign of low fluid levels.

Another most common and noticeable sign of low brake fluid is an illuminated ABS light on your vehicle’s dash. If this warning light comes on, it means that your brake system is not functioning correctly and needs to be checked immediately.

Another sign to look out for is Leaks. If you notice any leaks coming from the brake system, there is likely not enough fluid in the system. This can lead to decreased braking power and increased wear on the brakes themselves. Finally, if you notice that your brakes are making strange noises (squealing, grinding, etc.), this could indicate low brake fluid levels. If you notice any of these signs, it is important to have your vehicle inspected by a qualified mechanic as soon as possible.

How to Add Brake Fluid

The process of adding brake fluid is simple, but there are a few things you need to keep in mind. First, ensure your vehicle’s brake system is completely free of any air. Otherwise, the new brake fluid will mix with the air and become ineffective. Second, use only fresh brake fluid from a sealed container; old or contaminated fluid can cause problems in the braking system. Finally, ensure you’re using the correct fluid type for your car. Second, be careful not to overfill the reservoir

  • Park your car on a level surface and set the parking brake. This will help prevent the car from rolling while you’re working on it.
  • Locate the reservoir. It is usually located near the master cylinder, under the vehicle’s hood.
  • Once you find it, remove the cap and clean off any dirt or grime on the opening.
  • Next, use a funnel to pour the new brake fluid into the reservoir. Be careful not to overfill it; fill it to the “full” line on the side of the reservoir.
  • Finally, replace the cap and recheck the level after a few days to make sure that it hasn’t dropped.

How Long Does Brake Fluid Last?

A wise practice is to have the mechanic inspect the brakes & brake fluid during each oil change. This will help diagnose the condition of your brakes and whether they require new fluid. Most car owners often change the brake fluid each four to five years. However, below is a detailed guide on how long brake fluid lasts.

  • DOT 3 – 1-2 years
  • DOT 4 – 2-3 years
  • DOT 5 – 5 years
  • DOT 5.1 – 3-4 years

When to Change Brake Fluid?

It is advised to replace the brake fluid each 2 to 3 years or 24.854 to 37282 miles (40,000 to 60,000 Km). For the braking system to perform optimally, the brake fluid must possess various qualities and fulfil a specified standard.

You must consider the brake fluid quality and your driving patterns for a more precise estimate. For instance, sports vehicles change the fluid every 3100 to 6200 miles due to the vehicle’s obvious operating demands.

Additionally, it would be best to flush brake fluid every 30,000 miles or two years, whichever comes first.


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