Brake Fluids

Brake fluid is a hydraulic fluid designed to be used in hydraulic brake and clutch systems. Most types are  miscible with and will absorb water so it should be flushed every couple of years to make sure the brake system has as little water in it as possible. When water is introduced into the brake system, it will lower the boiling point of the fluid. This can cause a dangerous condition if the brake fluid boils under heavy braking – the resulting bubbles will significantly decrease the ability of the hydraulic system to apply the brakes or clutch.

DOT 3:
Most passenger cars on the road will be using DOT 3 brake fluid. This is the minimum allowable specifications to be road-legal. DOT 3 brake fluid can be mixed with DOT 4 and DOT 5.1 but will modify the ratings of the brake system to that of the lowest rated fluid. Minimum WET/DRY boiling points in degrees Fahrenheit: 281F/401F

DOT 4:
Higher-end passenger cars, sports cars, and heavy-duty cars typically use DOT 4 brake fluid. DOT 4 brake fluid can be mixed with DOT 3 and DOT 5.1 but will modify the ratings of the brake system to that of the lowest rated fluid. Minimum WET/DRY boiling points in degrees Fahrenheit: 311F/446F

DOT 5:
DOT 5 brake fluid is silicone-based requires a different brake system to prevent damage to seals and gaskets designed for a DOT 3 / DOT 4 / DOT 5.1 system. DOT 5 brake fluid CANNOT be mixed with DOT 3 / 4 / 5.1 brake fluid and is INCOMPATIBLE with seals and gaskets designed for DOT 3 / 4 / 5.1 brake fluid. Minimum WET/DRY boiling points in degrees Fahrenheit: 356F/500F

DOT 5.1:
This is the DOT 3 and DOT 4 compatible version of DOT 5 brake fluid. DOT 5.1 brake fluid can be mixed with DOT 3 and DOT 4 but will modify the ratings of the brake system to that of the lowest rated fluid. Minimum WET/DRY boiling points in degrees Fahrenheit: 356F/500F

There are a wide variety of brake fluids available to use, but listed below are brake fluids listed from lowest to highest boiling point. Generally speaking, the cheapest fluid will also have the lowest point point and will be the easiest to get. Some of the higher-end fluid are mail-order only or will be extremely difficult to get locally and will be significantly more expensive.

Valvoline Synthetic DOT 4:

• Manufacturer’s Information Link
• Fluid Color: Clear
• Availability: Any major auto parts store / Mail Order
• Wet / Dry boiling point in degrees Fahrenheit: 311F / 446F
• Market Unit Cost / Liter: $8 / 1 Liter

 

Pentosin Super DOT 4:

• Manufacturer’s Information Link
• Fluid Color: Amber / Light Yellow
• Availability: O’Reilly Auto Parts / Mail Order
• Wet/Dry boiling point in degrees Fahrenheit: 329F / 509F
• Market Unit Cost / Liter: $13 / 1 Liter

 

ATE Super Blue Racing DOT 4:

• Manufacturer’s Information Link
• Fluid Color: Blue
• Availability: Mail Order / Speed Shops
• Wet / Dry boiling point in degrees Fahrenheit: 388F / 536F
• Market Unit Cost / Liter: $20 / 1 Liter
• Note: Often alternated with ATE Type 200 during bleeding to ensure that all of the fluid is flushed. Has identical specifications with ATE Type 200. Questionable legality because official federal DOT 3 / 4 specification requires clear or amber / yellow coloration.

 

ATE Type 200 DOT 4:

• Manufacturer’s Information Link
• Fluid Color: Amber / Light Yellow
• Availability: Mail Order / Speed Shops
• Wet / Dry boiling point in degrees Fahrenheit: 388F / 536F
• Market Unit Cost / Liter: $20 / 1 Liter
• Note: Often alternated with ATE Super Blue Racing during bleeding to ensure that all of the fluid is flushed. Has identical specifications with ATE Super Blue Racing.

 

Motul RBF600 Factory Line DOT 4:

• Manufacturer’s Information Link
• Fluid Color: Amber / Light Yellow
• Availability: Mail Order / Speed Shops
• Wet / Dry boiling point in degrees Fahrenheit: 401F / 594F
• Market Unit Cost / Liter: $34 / 1 Liter
• Note: Higher viscosity that may be unsuitable for low temperature or electronic brake systems.

 

Motul RBF660 Factory Line DOT 4:

• Manufacturer’s Information Link
• Fluid Color: Amber / Light Yellow
• Availability: Mail Order / Speed Shops
• Wet / Dry boiling point in degrees Fahrenheit: 400F / 617F
• Market Unit Cost / Liter: $54 / 1 Liter
• Note: Higher viscosity that may be unsuitable for low temperature or electronic brake systems.