The brake system cannot function without brake fluid. There are several types of brake fluids to suit various types of conditions. It is essential to use the correct fluid for your car depending on the climate. These various brake fluids will vary in different dry and wet boiling points for safe use.
Dot 3 brake fluid
Dot 3 brake fluid is used by most cars and trucks. This is a polyglycol-based product. It has a dry boiling point of 401 degrees F and a wet boiling point of 284 degrees F. This can be efficiently mixed with Dot 4 and 5.1 brake fluids. It is recommended that this fluid be replenished every year in very humid climates and a year and a half for dry conditions. The boiling point is minimized when it absorbs moisture. This reduces the performance of the fluid. Makes the pedals feel fluffy. Dot 3 fluid can damage paints if it comes in contact with them.
Dot 4 fluid
For larger cars, Dot 4 is the preferred fluid. This is also used for the ABS braking system, for towing and high speed braking for cars at high altitudes. It has a dry boiling point of 446 degrees F and a wet boiling point of 311 degrees F. This can be mixed with Dot 3 and 5.1 fluids. This liquid is not absorbed quickly compared to the Dot 3, but the boiling point is minimized at a faster rate. Like the Dot 3, the Dot 4 should be changed once a year in wet conditions and every year and a half in dry conditions.
Dot 5 fluid
The Dot 5 is used in old or very old cars that have not been driven for many years. This type of brake fluid is not good for ABS systems. It is silicone based and does not mix with other types of fluids. It also won’t mix with water. The Dot 5 does not absorb air and will not soften the brake pedal. This is purple in color and will not damage paints. If you are considering using a Dot 5, be sure to consult a professional first.
Dot 5.1 brake fluid
This fluid has a higher dry boiling point of 500 degrees F and a wet boiling point of 356 degrees F compared to Dot 3 and 4. It is typically used in fleets and other trucks and heavy vehicles. This is also very popular in race cars. This is a polyglycol based product and will mix with Dot 3 and 4 brake fluids. Along with 3 and 4, the Dot 5.1 should be changed every year in humid climates and a year and a half in dry climates.