Brake fluid

Types of Brake Fluid

Brake fluid is a vital component in vehicles that helps to transfer force in the braking system, enabling effective and reliable braking. There are different types of brake fluids, each designed to meet specific requirements and preferences. The most common types of brake fluids are as follows:

• DOT 3

  DOT 3 brake fluid is one of the most commonly used types. It is a glycol-ether-based fluid that meets the Department of Transportation (DOT) standards. This brake fluid has a minimum boiling point of 401°F (205°C), making it suitable for everyday driving conditions. However, during heavy braking, it is prone to vapor lock. Vapor lock can be dangerous as it can cause brake failure. DOT 3 brake fluid is compatible with most braking systems. Nonetheless, it should not be mixed with mineral-based fluids.

• DOT 4

  DOT 4 brake fluids are also glycol-ether-based fluids. They have a higher boiling point than DOT 3 fluids. The minimum boiling point for DOT 4 fluids is 446°F (230°C). As a result, they are ideal for vehicles that require frequent heavy braking, such as trucks and buses. Moreover, they are less prone to vapor lock than DOT 3 fluids. This brake fluid has a higher viscosity than DOT 3 fluids. Thus, it can cause brake failure if the brake system components are not compatible.

• DOT 5

  Unlike DOT 3 and DOT 4 fluids, which are glycol-based, DOT 5 fluids are silicone-based. This makes them incompatible with the traditional glycol-ether-based fluids. This silicone-based brake fluid has a higher boiling point than DOT 4 fluids, making it suitable for high-performance vehicles. Also, it is not hygroscopic. Thus, it does not absorb water from the surrounding like the glycol-based fluids. As a result, it has a higher water content than the traditional fluids. Despite having some advantages over the other fluids, DOT 5 brake fluids are not widely used. This is because the existing brake systems in most vehicles are designed for the fluids that are hygroscopic.

• DOT 5.1

  DOT 5.1 brake fluids are also silicone-based. They are designed to be compatible with the existing braking systems. This makes it possible to use them as a replacement for DOT 3 and DOT 4 fluids. Moreover, it is not hygroscopic. Thus, it does not absorb water from the surrounding like the glycol-based fluids. As a result, it has a higher water content than the traditional fluids. Despite having some advantages over the other fluids, DOT 5.1 brake fluids are not widely used. This is because the existing brake systems in most vehicles are designed for the fluids that are hygroscopic.

Specification & Maintenance of Brake Fluid

Here are some brake fluids specifications that buyers should know before purchasing:

• Boiling Point

  Brake fluids have a high and low boiling point. The high boiling point is called ""BP-brake fluid"" and is suitable for high-performance vehicles. The low boiling point ""LP-brake fluid"" is compatible with general vehicles. Both fluids have a high boiling point of 230 degrees Celsius (446 degrees Fahrenheit) and above. The LP-brake fluid has a boiling point of 185 degrees Celsius (365 degrees Fahrenheit) and above.

• Viscosity

  Brake fluids have different grades of viscosity, which is the ability to flow through the braking system. The fluids are classified with the letter V followed by a number representing the grade. For instance, brake fluid can have a grade of V3, V4, or V5. The numbers are indicative of different viscosity levels.

• Corrosive Properties

  Brake fluids contain anti-corrosive components that minimize damage to the braking system's metal parts. The fluids are tested for corrosiveness to ensure they don't react with other components in the braking system.

• Compatibility with Seals and Hoses

  Brake fluids are tested to ensure they don't damage the seals and hoses in the braking system. The fluids are mixed with materials used to make seals and hoses, such as rubber, to determine any adverse effects.

• pH Level

  Brake fluids have a neutral to slightly acidic pH level of 6 to 8.5. The pH level is tested to prevent damage to the braking system's components.

Maintaining brake fluid is essential to ensure it works properly and to extend the life of the braking system. Here are some maintenance tips:

• 1. Check the brake fluid level regularly to ensure it doesn't fall below the minimum level.
• 2. Inspect the brake fluid for contaminants such as dirt particles, water, and air bubbles.
• 3. Replace the brake fluid every 2 years or after 240,000 kilometers (150,000 miles) of driving. The fluid should also be replaced if the quality deteriorates during inspection.
• 4. Drain all the old brake fluid before replacing it.
• 5. Ensure there are no leaks in the braking system.

How to Choose Brake Fluid

Choosing the right brake fluid for a specific vehicle is crucial for maintaining optimal braking performance and safety. Here are some factors to consider when selecting brake fluid:

• Compatibility

  Ensure that the brake fluid is compatible with the vehicle's braking system components. Different vehicles may recommend specific types of brake fluids, such as DOT 3, DOT 4, or DOT 5.1.

• Boiling Point

  Consider the boiling point of the brake fluid. Higher boiling points are essential for vehicles subjected to extreme conditions, such as towing heavy loads or driving in hilly areas. Fluids with higher boiling points offer better resistance to brake fade.

• DOT Standards

  DOT standards indicate the type and quality of brake fluids. For most passenger vehicles, DOT 3 or DOT 4 fluids are standard. DOT 4 fluids have a higher boiling point and are suitable for performance cars or those with heavier loads.

• Moisture Absorption

  All brake fluids are hygroscopic, meaning they absorb moisture from the air. This moisture can lower the boiling point of the fluid and affect braking performance. Choose a brake fluid with low moisture absorption to ensure long-lasting performance.

• Viscosity

  Consider the viscosity of the brake fluid. It should flow easily through the braking system, even at low temperatures. Fluids with high viscosity may cause brake lag and reduce overall braking efficiency.

• Quality and Brand Reputation

  Choose brake fluid from reputable brands known for quality and reliability. High-quality fluids meet industry standards and provide consistent performance.

• Color and Appearance

  While not a definitive indicator of quality, most brake fluids are amber to clear in color. Unusual colors or cloudiness may indicate contamination or degradation.

• Vehicle Manufacturer Recommendations

  Always consult the vehicle's owner's manual or contact the manufacturer for brake fluid recommendations. Using the recommended fluid is essential for warranty compliance and optimal vehicle performance.

• Price

  While it's tempting to go for the cheapest option, remember that with brake fluids, as with other products, you get what you pay for. Consider fluids with competitive pricing from reputable brands.

By considering these factors, vehicle owners can select the right brake fluid to ensure safety, reliability, and optimal braking performance in their vehicles.

How to DIY and Replace Brake Fluid

Changing brake oil is a crucial maintenance step that improves vehicle safety. While it might look complicated, replacing brake fluid is an easy DIY task with the right tools and knowledge. Before getting down to work, ensure the user's manual is within reach for specific details regarding the brake system. Here are some of the requirements needed to change brake fluids:

• New brake fluid
• Brake bleeder kit
• Wrench set
• Clear tubing
• Jack and jack stands
• Container for used fluid
• Gloves and safety glasses

With everything in place, follow the steps below to change the brake fluid successfully:

• 1. Lift the car with a jack and secure it with jack stands to prevent any accidents. Also, ensure the wheels are chocked to prevent the car from rolling.
• 2. Locate the brake bleeder screw on each wheel. It's usually on the brake caliper and looks like a small metal nozzle.
• 3. Put a clear tube over the brake bleeder screw and place the other end in a container. This helps collect old fluid.
• 4. Open the screw with a wrench and ask a friend to slowly press the brake pedal. The fluid will come out of the tube as they press down and then return. Don't forget to top up the reservoir.
• 5. Keep the screw open, and keep pressing the brake pedal until the fluid running out of the tube looks clean.
• 6. Once satisfied with the fluid, close the bleeder screw and remove the tube.
• 7. Repeat the process on all four wheels and ensure the brake fluid level in the reservoir is full.

Q&A

Q1: How often should brake fluid be changed?

A1: Generally, buyers can change brake fluid every two years or after 40,000 kilometers. However, the replacement interval may vary depending on the vehicle's use environment and the brake fluid's quality. In high-load conditions, such as frequent mountain roads or high-speed circuits, the replacement period should be advanced.

Q2: What are the steps for replacing brake fluid?

A2: First, buyers should choose a suitable brake fluid. Then, old fluid is drained from the brake system, and the new fluid is filled. After that, the system is bled to remove air, ensuring fluid cleanliness and level checking. Buyers can replace fluid themselves, but following detailed instructions is essential. If not, they can take the car to a professional maintenance shop.

Q3: Can different types of brake fluid be mixed?

A3: No, it's not recommended. Brake fluids of different types may have different chemical compositions, which could cause compatibility issues and damage the brake system. Buyers should stick to the type of fluid recommended in the vehicle's manual.

Q4: What is the importance of bleeding the brake system after changing the fluid?

A4: Bleeding the brake system is crucial to removing air, maintaining brake performance, and ensuring safety. Air in the system can compress, leading to a soft brake pedal and reduced braking efficiency. Therefore, buyers must bleed the system thoroughly after changing the fluid.

Q5: Are there any signs that indicate the need to change brake fluid?

A5: Apart from the scheduled replacement, buyers can look for some signs, such as fluid discoloration, a soft brake pedal (indicating possible air or moisture in the fluid), or reduced braking performance. If they notice these signs, changing the fluid is essential and taking the car to a professional mechanic for a thorough inspection.