Updated at: 19-07-2022 - By: Lucas

Many vehicle enthusiasts wonder if combining different brake fluids will have any negative effects. You can mix multiple brands of brake fluid, but they must all be the same grade.

Having a brake fluid with a lower boiling point is the worst-case scenario when mixing brake fluids of the same grade, such as DOT 3 and 4. The boiling points of fluids are listed in DOT specifications, not the manufacturers.

What brake fluids DOT can be mixed?

Can You Mix Brake Fluid

Because they all use the same glycol ether basis, DOT 3, 4, and 5. 1 can all be used together. Keep in mind, however, that the lowest DOT number is vital to keep in mind.

Mixing DOT 5 with any other DOT fluid is strongly discouraged. Silicone base means it is utilized by heavy vehicles and racing cars alike. Anti-lock brake systems are not compatible with silicone-based fluids (ABS). A DOT 5 brake fluid should not be mixed with other brake fluids for this same reason.

DOT 3 and DOT 4 are backwards-compatible. It’s something to keep in mind. The boiling point of DOT 4 is higher than that of DOT 3. As a result, the boiling point of the final mixture will be lower.

Because of its higher boiling point, DOT 5. 1 is often linked with heavy-duty trucks and sports automobiles. The DOT 3 and DOT 4 additives are safe to combine with it as well.

No other fluids can be used in conjunction with DOT 5, which has a water-resistant silicone basis. Cars with a heavy load might use the brake fluid, which can be stored for a long time. Take care not to brand some fluids that are incompatible while combining different types of brake fluid.

Can you mix old and new brake fluid?

We’ve determined that the brand of brake fluid doesn’t matter when it comes to blending brake fluids. Mixing two brake fluids that have the same constituents is simple.

Most folks then wonder if it’s possible to mix in new brake fluid with old.

New brake fluid cannot be mixed with old brake fluid. The brake system’s safety is jeopardized if you combine the two.

For fluids with identical constituents, you can only combine two new fluids together. It’s also a bad idea to combine various brake fluids, as it’ll result in a sloppy system and a terrible fluid.

When changing brakes and discs, be aware that combining old and new brake fluid will not improve the quality of the resulting fluid; rather, it will increase its volume, resulting in a sloppy mess in the engine compartment.

The most important thing to remember when combining brake fluids is to look for fluids with similar components. Because brake fluids collect water easily, you should replace them after the manufacturer’s specified time frame.

Consequently, if old and fresh brake fluids are mixed, the braking system will malfunction. Reusing brake fluid could jeopardize the safety of your car, so don’t do it.

The baked pads on a car’s brakes generate a lot of heat, which is then transferred to the brake fluid. The effectiveness of the braking system can be harmed if the fluid is polluted with water and then heated to evaporate the water.

Can you drive with mixed brake fluids for long?

Can You Mix Brake Fluid-3

The boiling point of braking fluids is lowered and their resistance to mixing with vapor is reduced when they are mixed together. You’ll wind up with something that won’t be useful for a long time when you try blending DOT 3 with DOT 4, or even with DOT 5.

Brake fluids that have been mixed together won’t stop your car as effectively, so don’t use the mixture for extended trips.

To avoid driving with mixed brake fluid, you should only do so if your brake fluid level is low and your preferred fluid is unavailable.

In addition, blending DOT 4 and DOT 3 brake fluids will result in a less noticeable performance differential. It’s important to keep in mind that the performance of your vehicle will be drastically reduced when DOT 5 is mixed with DOT 3.

You must ensure the brake fluid is free of contaminants because it is responsible for converting the force you apply to the brake pedal into pressure.

Friction generates a great deal of heat during the braking process, which in turn heats the baking fluid. Any substantial alteration to its features would reduce its efficiency, so it is not safe to drive with it for an extended period of time.

Water vapor has a lower boiling point than liquid water, making it more difficult to compress, resulting in a less efficient braking system if it gets inside the car.

As soon as possible after arriving at your location, get to the mechanic and clean out the brake system with DOT-approved brake fluid, then replace a new type of fluid recommended by your vehicle’s manufacturer.

What brake fluids DOT cannot be mixed?

Various brake fluids are manufactured with distinct chemicals and for different reasons, therefore it’s important to keep this in mind. Our braking fluids, on the other hand, are all synthetic, so keep that in mind.

Non-synthetic glycol-based braking fluids are compatible with DOT 3 except for DOT 5, which is synthetic. Changing the braking fluid to DOT 5 necessitates flushing of the braking system, as a result.

You should be aware of the DOT numbers and substances used when mixing brake fluids, though. The boiling point and water resistance of a brake fluid are shown in DOT ratings.

Glycol-based brake fluids, such as DOT 3, 4, and 5, can be mixed with no discernible performance difference.

Increasing the DOT number of the brake fluid results in an increase in the fluid’s boiling point. The mixture is only half-baked and will lose its potency over time.

In other words, if you’re going to mix brake fluids with various DOT ratings, you should aim to use one with a higher rating as soon as possible.

It isn’t required, but it’s highly advised, that you cleanse your brake system when you upgrade from the DOT 3 to the new DOT 4. Consider flashing your braking system before converting to DOT 5 brake fluid.

Final advice: When combining different brake fluids, consider each one’s unique characteristics instead of its manufacturer’s label. The fluids’ intended usage and compatibility might be influenced by the ingredients employed in their production. This means that only fluids that are compatible with one another can be mixed together.