Can You Mix Synthetic Brake Fluid With Regular Brake Fluid [Know A-Z]

You got a used car recently and noticed the clutch fluid is low. But you don’t know what kind of clutch fluid is in there. You get regular brake fluid. Now, you suspect there is synthetic brake fluid. So, the question that appears in your mind is- Can you mix synthetic brake fluid with regular brake fluid? Does it bring any damage to the brake system?

Well, you can mix the synthetic brake fluid with regular brake fluid if both the fluids are rated as Dot 3, 4, and 5.1. These brake fluids are glycol-based and all of them are compatible with each other.

So, mixing and putting the brake fluids will not bring any damage to your brake. However, it will be a big no if one of the oil is rated as Dot 5. We will break it down throughout this article. So, keep scrolling. 

Note: You can also read Can you mix different brands of oil.

Can You Mix Synthetic Brake Fluid With Regular Brake Fluid

You can mix synthetic brake fluid with regular brake fluid if they are rated as Dot 3, 4, and Dot 5.1. Keep in mind; all brake fluids are synthetic. So, you can mix them without any hesitation. The brake fluids rated as Dot 3, 4, and Dot 5.1 have progressively higher boiling points and are compatible with each other. 

On the other hand, you can’t mix the synthetic brake fluid with regular brake fluid if any of them is rated Dot 5. The Dot 5 brake fluid is silicone-based. So, it’s not compatible with synthetic oil. Basically, this brake fluid is made for racing cars. If you mix it with synthetic or regular brake fluid and put it in the engine, it will destroy every single brake component. 

In short, you can mix the synthetic fluid with regular brake fluid until they are rated as Dot 3, 4, and Dot 5.1. On the other hand, you should run away from mixing synthetic fluid with the brake fluid that is rated as Dot 5. 

What Happens If You Mix Synthetic Brake Fluid With Regular Brake Fluid

Nothing significant will happen if you mix synthetic brake fluid with regular brake fluid. Almost every brake fluid in the market is glycol-based. For example, the common synthetic brake fluids like Dot 3, 4, and Dot 5.1 you see are the same type of brake fluid. Mixing them with one another only increases the boiling point. You don’t feel any differences in performance. 

However, the scenario will be different when it comes to mixing these brake fluids with the fluid that is rated as Dot 5. The Dot 5 brake fluid is silicone-based. And we know silicone is not compatible with glycol. So, you can’t mix the Dot 3, 4 brake fluids with the Dot 5 brake fluids. If you dare to mix these brake fluids, it will ruin every component of your brake and cause brake failure. 

Can You Mix Mineral And Synthetic Brake Fluid

Yes, you can mix mineral and synthetic brake fluid without any issues. Both mineral and synthetic-based brake fluids are compatible with each other. In other words, the mixture of mineral and synthetic brake fluid will bring no damage to your brake components. 

Your braking system will absorb the mixture of these two different brake fluids. So, you don’t need to worry about brake failure. Indeed, it is safe to mix mineral and synthetic brake fluid.

FAQs:

Does synthetic brake fluid absorb moisture?

Every synthetic brake fluid blends with each other. But some brake fluids labeled as Synthetic are more resistant to absorbing moisture. However, some carmakers suggest periodic flushing, bleeding, and replacement. 

Are all DOT 4 brake fluids the same?

Yes, all DOT 4 brake fluids are the same. They are glycol-based brake fluids and compatible with each other. It means you can mix these brake fluids with each other without harming the brake system. 

What brake fluid can you mix?

Almost every brake fluid in the market is synthetic and they are glycol-based. It means you can mix every brake fluid that is rated as Dot 3, 4, 5.1. However, you can’t mix the Dot 5 brake fluid as it’s silicone-based. 

Can you mix DOT 4 synthetic brake fluid with DOT 3?

Yes, you can mix DOT 4 synthetic brake fluid with DOT 3 as they are compatible with each other. However, the Dot 4 synthetic brake fluid has a greater boiling point than the DOT 3. 

Conclusion

We hope you get the answer to this question: Can you mix synthetic brake fluid with regular brake fluid?

The short answer is- Yes if both the synthetic and regular brake fluid is rated as Dot 4, 4, and 5.1. All of them are compatible with each other as they are glycol-based. On the other hand, you can’t mix the brake fluid that is rated as Dot 5 with the synthetic or regular brake fluid. Because it is silicone-based. 

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