Posted under Car Fluids

When something is as important as brake fluid, the more you know, the better. That’s why we’ve collected the answers to commonly asked questions on this topic and posted here for your convenience, and safety!

Q: What is Brake Fluid?

A: It’s a hydraulic fluid that transfers force from the brake pedal to the braking components for all four wheels of your car. The pressure is essential for slowing and stopping the vehicle when the brakes are applied. It also lubricates the moving parts of the braking system and absorbs any moisture that gets into the brake hydraulic system.

Q: Why is My Car Leaking Brake Fluid?

A: Brake fluid leaks are often caused by a worn seal in the master cylinder, caliper, or wheel cylinder. If you suspect your car is leaking brake fluid, call a tow truck to take your vehicle to a service provider for a brake fluid inspection. Brake fluid leaks can lead to total brake system failure.  

Q: Wait! How Does Moisture Get into the Brake System Anyway?

A: Typically, water can enter through leaks in your rubber brake lines or worn seals in the master cylinder, calipers, or wheel cylinders.

Q: What Types of Brake Fluid Are Available?

A: Brake fluids are classified by the US Department of Transportation (DOT). There are two main types:

  • Glycol based (DOT 3, DOT 4, and DOT 5.1). These fluids absorb water and are used in most modern vehicles.
  • Silicone based (DOT 5). Silicone-based fluid does not absorb water.

The main difference between these fluids are the additives that enhance their boiling point, corrosion/rust resistance, or general wear. Some additives act as neutralizers or pH balancers. 

Q: What Type is Right for Your Car?

A: Follow your vehicle manufacturer’s recommendation for the proper fluid type for your specific vehicle. You can find this information by checking the owner’s manual or by looking on the master cylinder reservoir cap. If you can’t locate the manufacturer’s recommendation, a Jiffy Lube® technician can access this information for you.

Q: What Color is Brake Fluid?

A: Brake fluid is typically clear or may be dyed to have a slight orange, blue or green tint. If the fluid appears dark or murky, you should probably have it checked by a professional. 

Q: Can I Check the Brake Fluid Myself?

A: If you’re a DIYer, here’s how to do it. But before we begin, please remember that brake fluid is toxic and should be handled with care.

  • Identify the car’s master cylinder. Located under the hood, the simple plastic container is typically on the driver’s side of the vehicle placed against the bulkhead.
  • Check the fluid level by inspecting the side of the plastic reservoir and making note of the fluid level, compared to the FULL or MAX line.
  • If your car is older, it may be necessary to remove a metal cap to check the level. Pay special attention to keep debris from falling into the reservoir.
  • Replace the cap or top and close your hood.

You can also bring your car to Jiffy Lube®, where a trained technician will check the fluid as part of a brake fluid inspection.  With more than 2,000 locations across the country, there is a service center near you.


Q: What Can I Expect When I Bring My Car to Jiffy Lube® for Brake Service?

A: Jiffy Lube® technicians are trained in maintaining your brake system. 

  • Expect questions about your driving style. For example, knowing that you frequently drive in stop-and-go traffic, travel long distances, or often tap the brake pedal as you drive downhill will help the technician trouble-shoot your brakes.
  • If your manufacturer recommends multiple brake fluid replacement intervals, the technician will help you decide how to proceed.
  • Before any service is performed, you will be presented with an estimate of total costs and a timeframe in which the service will be completed.
  • Where applicable, Jiffy Lube® uses Pennzoil® products which meet or exceed Original Equipment Manufacturer (OEM) recommendations.


A Jiffy Lube technician handing a woman back her car keys after conducting a brake fluid inspection

Q: How Often Should I Change the Brake Fluid?

A: Some manufacturers recommend that brake fluid be replaced every two years or 30,000 miles. Others recommend three years or 45,000 miles. And some manufacturers make no recommendations at all! If you can’t find the manufacturer recommendation for your specific vehicle, ask a trained Jiffy Lube® technician.

Q: What Are Signs That a Brake Fluid Inspection Is Recommended?

A: Six things to watch out for:

  1. The Antilock Brake System (ABS) light is illuminated. This light doesn’t only come on when the brake fluid is low or needs replacement, it also reminds you when a brake fluid inspection is needed. 
  2. Change in feel. You may notice the brake pedal is soft, loose, bouncy, or goes to the floor.
  3. Strong burning smell when you press the brake. This could mean the brake fluid is burnt and needs to be replaced.
  4. A loud, squealing, or squeaking sound from the brakes. Your brakes are telling you it’s time for a brake inspection.
  5. If your brakes aren’t as responsive as usual, it could be warped rotors, worn pads, or contaminated brake fluid.
  6. Leaking brake fluid. If you notice leaking brake fluid, have your car towed to a service center before you experience a total brake system failure. 

Q: How Does Brake Fluid Cause the Car to Stop?

A: The relationship between the fluid, the hydraulic braking system, and vehicle motion is an example of Pascal’s law. This principle states that when a fluid experiences any type of pressure change in an enclosed space, the pressure is transmitted equally in all directions. 

Let’s illustrate this by explaining how the system would work as a driver approaches a red light:

  • When the driver applies the brake, a rod forces a piston into the master cylinder, creating pressure 
  • The pressure is distributed throughout the braking system by forcing the fluid throughout the brake lines into the brake calipers
  • This pressure is applied to the piston(s) inside the brake calipers
  • These pistons then apply the force to the brake pads and the rotor, so the vehicle slows and then stops as the car reaches the stop light

Read More About It

Now you know what’s up if your car is leaking brake fluid, but what if you spot a puddle of transmission fluid? Find out what to do here.

Please note: Not all services are offered at each Jiffy Lube® location. Please check with your local Jiffy Lube® service center or visit for specific services offered.