Can I use DOT 5 brake fluid in my classic car?

Classic car owners may want to use DOT 5 because it has a higher heat capacity than DOT 3 and DOT 4 and will not strip paint if it leaks. But, overall, this brake fluid is not a good choice if you want your braking system to perform safely and efficiently.

Should I use DOT 4 or 5 brake fluid?

DOT 4 has a boiling point of 311 degrees F., and it is rated at a viscosity of 1800 at -40 F. DOT 5 is silicone-based brake fluid and is used in most new cars today. DOT 5 is expensive, but it has a dry boiling point of 356 degrees.

Can I use DOT 5 brake fluid instead of DOT 4?

No, DOT 4 is glycol-based, making it fundamentally incompatible with DOT 5 brake fluid.

Can you mix DOT 3 and DOT 5 brake fluid?

All DOT 3, 4 and 5.1 brake fluids are compatible with each other and with all systems. All polyethylene glycol-based fluids will not harm healthy rubber parts. Also, the additive packages will not damage or distort any rubber parts.

What’s the difference between DOT 4 and DOT 5.1 brake fluid?

DOT 5.1 fluids are a development of DOT 4 having not only higher boiling points (and retaining them even better than DOT 4 in service) but also having a much improved viscosity (thickness) at low temperatures.

What happens if you mix DOT 3 and DOT 5 brake fluid?

Can I mix DOT 3 and DOT 4 brake fluid?

Can you mix Dot 3 and Dot 4 Brake Fluid? Yes, Dot 3 and Dot 4 brake fluid can be mixed. 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.

Can you use DOT 5.1 instead of DOT 4?

Since DOT 4 and 5.1 are both glycol-based brake fluids they are compatible with each other, which means they can be readily mixed without harming your brake system.

Is DOT 3 or DOT 5 better?

With such impressive numbers, DOT 5 is better resistant to rust and corrosion and lasts longer than DOT 3 or DOT 4.

What happens if I use DOT 3 instead of DOT 4?

DOT 3 brake fluid will absorb less water than DOT 4 from the air over time, meaning you’ll need to have your fluid changed less frequently. DOT 4 brake fluid has higher dry and wet boiling points, making it safer for higher temperatures.