Do you own a motorcycle and a car? Have you ever thought that you could use their brake fluids interchangeably? If so, you are not alone. And in this guide, we are going to sort this matter once and for all. So, is motorcycle brake fluid different from a car?
No, you can use your motorcycle’s brake fluid in your car without any hassles. But there are a few things that you need to keep in mind.
Both vehicles use this fluid in their braking systems. It has nothing to do with their engines, so you can use a single fluid in both your vehicles. The braking mechanism of both these vehicles works the same, so there is no need to have a different fluid.
But you need to give a little thought to their DOT ratings. If these ratings are the same, you can use the same fluid in both. So now, what are these DOT ratings? Scroll down to read further and understand if the motorcycle brake fluid is different from a car.
Are Motorbike and Car Brake Fluids Same?
So, can you use these fluids interchangeably? Motorcycle brake fluid is not different from a car’s brake fluid. So, you can use the same fluid if you want to.
If you are using a DOT 4 fluid in your motorcycles, you can also use that in your car. They both use the same fluid. But there are different types of braking fluids that you must consider. DOT 5.1, DOT 5, DOT 4, DOT 3 brake fluids, etc.
The different types of these fluids have various boiling points. However, if your motorcycle has DOT 4 brake fluid recommendation, you can use the same fluid in both your vehicles.
There is no distinction whatsoever that you have to deal with. But things will be slightly different if both your vehicles have different DOT ratings. So, let us further our discussion on “is motorcycle brake fluid different from a car”.
Brake Fluid Types
So, what are different brake fluid types? DOT rating is what classifies and rates different types of brake fluids. DOT refers to the Department of Transportation. The numbers preceded by the DOT abbreviation denote various kinds of fluids and their boiling points.
Therefore, with a higher DOT number, the boiling point of that particular brake fluid will be higher. For example, DOT 5 brake fluid has higher boiling points than DOT 4 or DOT 3.
The following table elaborates different boiling points of varying brake fluids:
| Brake Fluid | Boiling Point (Dry) | Boiling Point (Wet) |
| DOT 3 | 401F or 205C | 284F or 140C |
| DOT 4 | 446F or 230C | 311F or 155C |
| DOT 5 | 500F or 260C | 356F or 180C |
| DOT 5.1 | 518F or 270C | 374F or 190C |
DOT 4 is the braking fluid that is widely used in motorbikes. This brake fluid has subcategories such as DOT 4 Racing, DOT 4 Low Viscosity, DOT 4 Plus, etc.
DOT 3 or DOT 4 absorb water, while DOT 5 doesn’t. Apart from that, DOT 4 and DOT 3 can absorb paint too. Moreover, DOT 5 is pretty expensive, and it costs four times more than a DOT 3 brake fluid.
Here are some rules that you need to keep in mind about these fluids:
Don’t mix these fluid types
You cannot mix one brake fluid type into another one. A DOT 5 is the one that you have to be most careful about because it should not be combined with any other kind, no matter what.
However, you can technically mix DOT 4 and DOT 3. But that doesn’t mean you can mix them because they still tend to react in a bad manner and corrode your entire braking system.
Don’t use DOT 3 in your motorbike
DOT 3 brake fluid has a shallow boiling point. It means that the braking system of your motorbike will not operate properly with this braking fluid type.
Always pick the right fluid for your vehicle
You need to check your motorcycles’ owner manual to see what type of brake fluid is recommended. Then, be sure to stick with that type to make sure your bike’s braking system works appropriately.
Change your brake fluid every two years
To keep your motorcycle’s braking system in its top condition, you need to drain out the current brake fluid completely. Then, replace it with the new one, and you will not have any trouble with your braking ever.
Can New Brake Fluid Mix into Old One?
There shouldn’t be any problems mixing new brake fluid into old one. But vehicle manufacturers do not recommend mixing new brake fluid into the old one.
It is because the water or moisture content that your old brake fluid has absorbed will still be there. And it will mess up the moisture content of your new brake fluid with it.
Apart from the moisture content, various contaminated particles infiltrate your brake fluid. These contaminants will not go anywhere unless you drain the brake fluid.
Therefore, by adding some new brake fluid, you cannot improve the overall performance of the old brake fluid, and your braking performance will deteriorate.
As long as your old braking fluid remains in your bike’s system, the braking performance will not improve. Moreover, the current old braking fluid will decline its quality even further with time.
Therefore, you must ensure that you do not mix your new brake fluid with the old one. Topping up your brake fluid is fine if your fluid is not too old. But it is highly recommended that you drain out the old fluid entirely before using the new one.
How Often Should Brake Fluid be Changed?
So, should I change the brake fluid with each motorbike tuning? The ideal change interval for these fluids in motorcycles is two years. After that, it is the time when you need to drain the old brake fluid entirely and fill in the new one.
It is primarily because the brake fluid has absorbed water over time. With this absorption, brake fluids begin to deteriorate as they begin to corrode metal components that are there in your braking system.
With consistent brake fluid changes, you will ensure that your braking system continues to perform at its best. Apart from that, you will not have to worry about any corroding components in your braking system.
Are All DOT 4 Brake Fluids Same?
What types does DOT 4 brake fluid have, and how are they different? DOT 4 brake fluids you use in your motorcycles are similar to those in cars.
It is because they have the same characteristics and a similar boiling point. This is the primary reason why DOT 4 brake fluids are popular among all automobile owners.
Nevertheless, DOT 4 has different variants. For example, you will find DOT 4 Racing, DOT 4 Low Viscosity, DOT 4 Plus, etc. These DOT brake fluids are slightly different as they have varying hygroscopic traits and their boiling points are somewhat different.
What Brake Fluid Do I Have in My Motorcycle?
You might not have changed your brake fluid once you have bought it, thinking what type d you have in it, right? If you want to change your brake fluid for the first time and do not know what type you have, you can determine it by looking at your motorcycle’s owner’s manual.
Go to the specs section in the owner’s manual and see your bike’s brake fluid type. Your motorcycle manual will tell you about the brake fluid in both your front and rear braking system, and it will be the same.
If you change the brake fluid on your own or through a service shop or your dealer, you need to recall the type of fluid you used or ask them about it.
Remember, you cannot mix your new brake fluid into your older one. But is motorcycle brake fluid different from a car? No, it’s not, and you can use them interchangeably.
How to Know that My Brake Fluid Has Gone Bad?
But what will tell you that your brake fluid has gone bad? If you cannot apply brakes smoothly enough and are having trouble in your motorbike, your brake fluid has gone bad in terms of its performance and quality.
When it deteriorates, and your braking system is not working smoothly, it is time to change your brake fluid and use a new one. Brake fluid deteriorates in quality over time as it absorbs more moisture content and has contaminants in it.
These contaminants and a high moisture content begin damaging and corroding your braking system and its overall functionality. So as soon as you find that your braking system is not working, change the fluid as it has gone bad.
FAQs
Can I use my car brake fluid on my motorcycle?
You can use your car brake fluid in your motorcycle and vice versa. But keep the DOT rating in mind. Also, it is not recommended to mix different brake fluid types.
What type of brake fluid should I use in my motorcycle?
Most motorcycles use DOT 4 brake fluids. DOT 4 brake fluid has different types. You can go for DOT 4 Racing, DOT 4 Low Viscosity, DOT 4 Plus, etc. Check your owner’s manual for the recommended brake fluid for your motorbike.
Can I use DOT 3 instead of DOT 4?
DOT 3 has a lower boiling point than DOT 4. Therefore, it will get hotter much quickly than DOT 4 and start fading your brakes. Neither of them has low braking power. So, there is no reason for you to go for DOT 3 instead of DOT 4.
Can I use DOT 5 instead of DOT 4?
You can upgrade your brake fluid and go for DOT 5 from DOT 4. But make sure to drain out all old brake fluid before you go out in the new DOT 5. This brake fluid is compatible with poly-glycol-based anti-lock braking systems
Conclusion
So, is motorcycle brake fluid different from a car? No, it is not, and you can use the same fluid in both your vehicles. But keep in mind that the DOT ratings should be the same. This is because these DOT ratings change brake fluid’s hygroscopic traits and boiling points.
Therefore, you cannot mix different types of brake fluids. If you want to change the brake fluid type, dry the old one entirely and fill the new one. You can top off with new brake fluid as long as the old brake fluid is not too old.
