How Often To Change Brake Fluid On Motorcycles? – (5 Signs)

Modern motorcycles have a hydraulic braking system that makes the braking more effective and easy. The hydraulic brakes use a special fluid with a lower viscosity and a high boiling point.

Over time, the brake fluid absorbs moisture and dust, which reduces the effectiveness of braking and should be changed.

So, how often should you change your motorcycle brake fluid? You must change your motorcycle brake fluid after every two years for effective and reliable braking. However, riding off-road (in dust and mud) will attract dust and moisture faster, and brake fluid must be changed more frequently in that situation.

So, if your motorcycle brake lever feels spongy or slippery while pressing, then brake fluid could be the culprit and should be changed immediately.

In this guide, you’ll know the signs that indicate your brake fluid needs to be changed. Also, I’ll explain what type of oil should be used as brake fluid and how to change the brake fluid on any motorcycle.

How To Tell If Your Motorcycle Brake Fluid Has Gone Bad?

If you press the brake paddle, the fluid compresses, which presses the brake pads. Due to frequent compression, the viscosity of brake fluid decreases.

If your brake feels spongy or too hard while pulling the lever, it means your brake fluid has absorbed the moisture and needs to be replaced.

Following the obvious signs of bad brake fluids–

• Your brake will feel spongy while pressing the lever.
• The braking might fail intermittently.
• The brake paddle will feel hard sometimes.
• The brake fluid will look darker.
• The brake fluid level drops frequently.

Why Should Motorcycle’s Brake Fluid Be Changed?

The brake fluid has a lower viscosity and higher boiling points. So, when you press the brake lever, the fluid molecules compress, and it gets hot due to the extreme compression of molecules.

Over time, the viscosity of brake fluid increases due to dust and moisture, which disturbs the braking efficiency and makes the brake lever hard to pull. That’s why motorcycle manufacturers recommend changing the brake fluid every two years.

When To Change Motorcycle Brake Fluid?

If you are a heavy motorcycle enthusiast and often participate in bike racing, you should check the brake fluid monthly and top up whenever the level drops below the recommended level.

The brake fluid should be changed every two years when its color turns dark or if any dust particles are present.

What Happens If You Don’t Change Motorcycle Brake Fluid?

Let’s hypothetically assume- “that you’re riding your motorcycle over 120 MPH, and a situation arises where you must stop the bike for some reason, but its braking system fails“.

This situation will become true when you don’t change your brake fluid for longer. If you don’t change the brake fluid, it will absorb moisture and dust, which drops the braking system’s effectiveness.

What Type Of Brake Fluid Is Needed For A Motorcycle?

The motor vehicle mainly uses three brake fluid types: DOT 3, DOT 4, and DOT 5. Motorcycle manufacturers use DOT 3 and DOT 4 brake fluids, while DOT 5 is used in cars and trucks. But you should refer to the user manual for actual information.

This information is also mentioned on the brake fluid reservoir. So, you should always use the recommended brake fluid for your motorcycle.

Are Car And Motorcycle Brake Fluid The Same?

There is no difference between car and motorcycle brake fluids. You can use car brake fluid in a motorcycle if the DOT rating is the same.

Generally, most car manufacturers use DOT 4 brake fluid with a higher boiling point. This information is also mentioned on the cap of the fluid reservoir.

Can You Use Engine Oil As Brake Fluid?

The purpose of engine oil is to lubricate the engine’s moving parts, while brake fluid creates pressure on the brake pads.

You can not interchange the brake fluid with engine oil because it has a higher viscosity. If you use engine oil as brake fluid, additives will damage the rubbers, and you may face leakage.

I have written a detailed guide on why you should not use engine oil as brake fluid. Please read this guide.

Conclusion

Motorcycle manufacturers recommend changing your brake fluid every two years. However, you may need to change it if the fluid turns dark. Most motorcycles use DOT 3 and DOT 4 brake fluids; you can change them yourself. I hope you found this guide helpful, and keep changing your motorcycle brake fluid regularly.