Is DOT 5.1 better than DOT 4?

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.

Why is DOT 5 not recommended?

To get a better handle on why we don't recommend DOT 5 for our brake kits, we need to take a crash course in chemistry. Common brake fluids such as DOT 3, 4, and 5.1 are mixtures of glycols and glycol ethers while DOT 5 is silicone based.

What is DOT 5.1 brake fluid used for?

Application. DOT 5.1 Brake Fluid is recommended for re-fill or top-up of brake and clutch systems in passenger cars, 4WD's, motorcycles, light and heavy-duty commercial vehicles, mining, construction, agricultural and all other moving vehicle types that require a non-petroleum based brake & clutch hydraulic fluid.

What is the difference between DOT 4 and DOT 5?

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.

What happens if you put DOT 4 instead of DOT 5?

No, DOT 4 is glycol-based, making it fundamentally incompatible with DOT 5 brake fluid. If your fluids do get mixed, you'll need to flush the entire system multiple times to remedy the situation.

Brake Fluid Basics: DOT 3, 4, 5, and 5.1 Explained | MC GARAGE

Does DOT 5.1 damage paint?

All DOT 3, DOT 4 and DOT 5.1 fluids — the numbers refer to U.S. Department of Transportation specifications — are conventional glycol/ester-based hydraulic fluids, meaning they can and will damage paint if spilled on automotive bodywork.

Does DOT 5.1 absorb water?

Glycol fluids like DOT 3, DOT 4 and DOT 5.1 are actually designed to absorb water instead of separating like DOT 5. This water absorption means glycol-based fluids are “hygroscopic”.

When should I use DOT 5 brake fluid?

A DOT 5 brake fluid does not absorb moisture and does not affect painted surfaces, making it ideal for high-performance vehicles. Using this brake fluid protects the braking system from the effects of bad weather.

When did Harley stop using DOT 5?

DOT 5 brake fluid is stipulated for nearly all motorcycles from Harley-Davidson and Buell roughly from model years 1976 to 2004/2005 with original braking systems.

What happens if you use wrong brake fluid?

Using the wrong fluid can cause poor lubrication, overheating, and possibly transmission failure. A mechanic might not be able to reverse the damage, even by flushing the transmission. Mistakenly adding motor oil or brake fluid can also destroy your transmission.

Is all DOT 5.1 brake fluid the same?

DOT 5.1 is totally different than DOT 5 brake fluid. Think of 5.1 as a glycol based DOT 4 fluid that meets DOT 5 silicone-based fluid standards. The 5.1 fluids are used primarily in vehicles equipped with ABS brake systems.

Which brake fluid is best?

What is the difference between DOT 3 DOT 4 DOT 5.1 and DOT 5 brake fluid?

DOT 5.1 is used in high-performance and heavy-duty applications due to its high boiling point. It's compatible with DOT 3 and DOT 4 fluid. DOT 5 brake fluid is silicone, meaning it doesn't absorb water.

Does DOT 5 damage seals?

DOT-5.1 is not the same as DOT-5. DOT-5.1 is more like a traditional glycol based brake fluid. DOT-5 is silicone based as mentioned above. DOT-5 does NOT eat seals.

Can you mix DOT 4 and DOT 5 brake fluid?

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. It is important never to mistake DOT 5.1 (glycol-based) with DOT 5 which is silicone-based and should never be mixed with any other DOT fluid.

Does DOT 5 brake fluid go bad?

Castrol recommends that DOT fluid in previously opened containers should be discarded after 12 months.

Can I use DOT 5 in my Harley?

Top reviews from the United States

I flush the DOT 5 brake fluid in my Harley every year using speed bleeders and I use DOT 5 from Belray and from Harley alternating the Belray and Harley brake fluid each year.

Do all Harleys use DOT 5 brake fluid?

DOT 5 Silicon Brake Fluid. For use in all models (except '21-later Revolution Max, '06-later VRSC^™, '07-later XL, '08-later XR, '06-later Dyna^® and Softail^®, and '05-later Touring and Trike models).

Can I use DOT 4 in Harley?

Harley-Davidson motorcycles use either DOT 4, which is glycol-based, or DOT 5, which is silicone based. Beginning in 1976, Harley-Davidson used DOT 5 in all its brake systems. For model year 2005, the FL platform changed to DOT 4. For 2006, all models except XL went to DOT 4.

Is all DOT 5 brake fluid purple?

New glycol-based fluid (DOT 3, DOT 4, DOT 5.1) is a translucent yellow color. In fact, it almost looks clear when you pour it out of the bottle. Fresh DOT 5 brake fluid is a purple color. This allows you to easily distinguish between glycol- based and silicone-based brake fluid.

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.

Is DOT 5 brake fluid silicone based?

It is important never to mistake DOT 5.1 (glycol-based) with DOT 5 which is silicone-based and should never be mixed with any other DOT fluid.

What are two advantages of DOT 5 brake fluid?

1) It has a high boiling point since it does not absorb water. Therefore, there's no so-called wet boiling point. 2) Doesn't absorb moisture. 3) Doesn't remove paint.

Should I use silicone brake fluid?

SILICONE BRAKE FLUID is non-toxic and non-corrosive and will not damage automotive painted surfaces, hoses, seals or other materials. It is compatible with most modern braking system components including seals, calipers and brake hoses. It should be changed according to the manufacturers specifications.

Does DOT 4 absorb more water?

Basically, the higher the DOT number, the more rigorous the specifications for the fluid, however, import manufacturers are equally divided between DOT 3 and DOT 4. The DOT 4 fluid absorbs less moisture and maintains a higher boiling point than DOT 3 fluid.