What Kind Of Brake Fluid Goes In A Go-Kart?

If you’re new to karting it might be overwhelming to try and find all the lubricants you need for your kart. Many people make the mistake of using the incorrect brake fluid in their karts, and this will ultimately ruin the system and lead to brake failures.

Go-karts use glycol-based brake fluids. You should be using DOT 5.1 fluids (not DOT 5). The only other brake fluid that might be compatible with your kart is DOT 4. If you use any other kind (DOT 3, or even DOT 5) you risk destroying your braking system.

Using the right brake fluid for your kart is extremely important. It will help your brakes to work properly and for much longer. It’s recommended to check your kart’s manual to double check that you are using the right brake fluid. Let’s take a closer look at karting brake fluid.

Why It’s Important To Use The Correct Brake Fluid

All brake fluids are different. The type of brake fluid you use in your system is crucial. That’s because the brake system is built to be able to use a specific brake fluid. Brake fluid is needed in order to compress the brake lines and apply pressure to the brake disc. However, using the brakes generates heat. Too much heat in the brakes can cause them to fade or even fail altogether.

This is why each brake fluid has a different boiling point. It’s important to pay attention to the boiling point needed for your brake system. If the boiling point is too low, the brakes will fail. Most kart brakes work hard and so a higher boiling point is needed.

DOT Numbers

Your brake fluids are differentiated by their DOT (Department of Transport) number. The higher the number, the higher the boiling point of the brake fluid. For example, the boiling point of DOT 3 brake fluid is 401 degrees Fahrenheit. The boiling point of DOT 5 for example is 500 degrees Fahrenheit.

However, it’s not just the boiling point of the brake fluid you need to worry about. The other thing you need to look at is the composition of the brake fluid. In other words, what is it made of?

Silicone-Based vs Glycol-Based Brake Fluid

There are two main types of brake fluid. These are silicone-based and glycol-based. There are some very important differences between the two. Using the wrong one in your brake system could destroy it.

Glycol-Based Brake Fluid

Glycol-based brake fluid is the most commonly used in the automotive industry, and it’s also the one that you will be using in your kart. There are several reasons this brake fluid is the best type to use in your kart.

Firstly, the glycol-based brake fluid can mix with water. This is crucial because of the way that a kart’s brakes are designed. Although the master cylinder is sealed, it is still exposed to the elements. When it rains, there is a huge possibility of moisture getting into the system.

This doesn’t just happen when it rains. Moisture can also get into your brake system when you drive through puddles or wash your kart. There can also be a buildup of moisture in the system if the kart is not stored properly in a dry area.

The Effect Of Moisture

Moisture in your brake system can prevent it from working properly. You will notice this if the brakes are fading, and the pedal begins to go closer to the floor than usual. Your brake pedal is supposed to be stiff, so this is a sign your brake system is on the way out.

While the glycol-based brake fluid can absorb moisture and still work decently, it is important to change your brake fluid regularly for this reason. At some point, too much moisture will begin to affect the way the brake fluid works.

Whenever moisture is absorbed into the brake fluid, its boiling point is reduced. In your kart this is an important factor, more so than in cars. Lower boiling points will mean poorer brake performance and a higher possibility of brakes overheating and failing.

Silicone-Based Brake Fluid

Silicone-based brake fluids have lower boiling points than glycol-based fluids. This means they are used for less high-pressure situations where the brakes are not used as often. This makes them much less compatible for karting.

Silicone-based brake fluids compress much more, and this makes the brake pedal feel spongier and softer as opposed to a stiff pedal in a system that uses glycol-based fluids. These brake fluids are mostly used in vintage cars and heavy-duty vehicles as well as military vehicles.

However, silicone-based brake fluid does not mix with moisture and water. This means that if any moisture were to get into the brake system you would need to flush the entire system as the brakes would not work.

How To Check Your Brake Fluid Type

Because we now understand how different types of brake fluids interact with water, we can use this knowledge to check what type of brake fluid is in our system. Although your kart is likely to have glycol-based fluid, it can still be helpful to double check it.

In order to check the brake fluid in your system you can take some of the brake fluid that is in your system and put a couple of drops in a bowl of water. If the fluid does not mix and floats at the top like olive oil would, you have a silicone-based brake fluid. However, if the brake fluid mixes in with the water, you have a glycol-based fluid.

Which Type Of Brake Fluid Should You Use?

When it comes to karts, their brake systems are extremely sensitive. Karts only have one brake on the rear axle, so it is critical that it works properly. This is why it’s so important to use the correct brake fluid with your kart.

Since the braking system of a kart is exposed to the elements, you need to make sure that if there were any moisture in the system the brakes would still be able to work. This means you need to ensure that you use a glycol-based brake fluid.

DOT 4 vs DOT 5

That leaves us with DOT 4 and DOT 5.1 brake fluids to choose from. The next step is to determine how hard the brakes work. Karting brakes work hard since there is only one, and it needs to slow the kart down very often (multiple times per lap) and very quickly (often in less than 50 meters).

This means we need a brake fluid with a high boiling point. This leaves us with DOT 5.1 brake fluid being the best option for our karts. However, Rotax also recommends using DOT 4, so if you can’t get a hold of DOT 5.1 it’s not the end of the world.

Things To Remember

Here are the most important things to remember when it comes to brake fluids in go karts:

  • Always make sure you use the correct type – In most cases, karts use glycol-based brake fluids and not silicone-based ones. This is the most important thing to remember, as using the wrong one can ruin your brakes.
  • Make sure you use the correct boiling point – Karts are hard on their brakes, so they will naturally need a higher boiling point. Ideally you should go for DOT 5.1 brake fluid.
  • Make sure not to mix different brands or types – If your system uses one type or brand, it’s best to stick with the same brand. Different brands can make their brake fluids out of different compositions, which may upset the brake system.
  • Always flush the system when changing brake fluid – It’s best to flush the entire system and bleed the brakes when you replace the brake fluid in the system. Any old, excess fluid can contaminate the new brake fluid.
  • Always ensure the master cylinder is tightly sealed – If any moisture or air was to get into the system it could cause the brakes to fade which will make the brake pedal feel weak and spongy.

Final Thoughts

There are lots of brake fluids to choose from, and it can be overwhelming trying to find the right one for your kart. Most karts use DOT 5.1 glycol-based brake fluid. Always try to use the same brand of brake fluid to ensure consistency.