DOT 3. Vs. Different Brake Fluids for DOT 3 and DOT 4. (Can you Mix them?

You want your brake system to work in emergencies.

Brake fluid should be replaced every one to two years. Otherwise, it can cause corrosion and damage other parts.

You can choose from silicone or glycol-based brake fluids. Dot3 or Dot4 can be used to brake many cars with glycol-based fluids. Dot3 is more popular among normal drivers than Dot4 in older cars.

However, what are the differences between these two? And can they be mixed together?

Dot 3 and. Dot 4 Brake Fluid Differences

There are two main difference between Dot 3 brake fluid and Dot 4 brake liquid. The boiling point. Dot 4 brake fluid has a lower wet boiling point, but it is more suitable for high performance.

Dot 3 brake fluids and Dot 4 brake liquids can be used to lubricate your brake system. These fluids are highly hygroscopic, and they absorb water from the air. Therefore it is important to take care when replacing or storing potentially dangerous fluids.

Is it possible to mix Dot 3 Brake Fluid and Dot 4 Fluid?

You can mix Dot 3 brake fluid and Dot 4 brake liquid. It’s because both these are glycol-based brake fluids, which means that they are compatible with each other. If your car has Dot 4 from the factory, it’s not recommended to fill it with Dot 3, though; but the other way is fine.

Dot 3 is a standard part of your vehicle. If you drive a lot, or are frequently driving in the hills with a trailer, it's advisable to refill it with Dot 4.

Is it possible to mix Dot 5 and Dot 3 or 4?

Dot5 is an ABS-compatible brake fluid that's silicone-based. This fluid is compatible with ABS systems and does not absorb water. It works great and maintains its integrity. This fluid also has a lower boiling point than brake fluids DOT3 and DOT4, making it easier to drive aggressively.

Dot3 and Dot4 fluids are not compatible, so you should never mix it with them. You must also follow your manufacturer’s recommendations to know whether your braking system is compatible with Dot5 brake fluid.

What does the boiling temperature mean?

Dot 3 brake fluids and Dot 4 brake fluids, as we have already mentioned, are hygroscopic. This means they can absorb water. It is important to replace the fluid every other year.

If you push your car at high speeds or pull a trailer, brake fluid heats up quickly. If it is heating up too much and starts to boil – you will lose the ability to brake your car, which is the least you want to happen at a hill with a trailer. It is crucial to maintain a maximum boiling point.

The brake fluid's wet boiling point can be measured if it contains water. However, its dry boiling point cannot contain water.

Dot3 and Dot4: What is the best brake fluid?

Dot3 is most popular, however Dot4 quickly gained popularity due to its compatibility with standard anti-lock brake system.

Dot 4 is more boiling point stable, which makes it better for many applications. It is also less expensive but well worth the extra cost.