Difference between DOT 3 and DOT 4 Brake fluid.

Brake fluid is concerned with DOT 3 and DOT 4. You might have heard about this if you got any brake-related problem in your car.

Any vehicle whether it is lightweight or heavy, brake fluid plays a vital role in the braking system. Required qualities and properties should have been there with brake fluid. In this aspect, brake fluid got property changes over a period of time. 

Brake fluid should be good and clean. Its viscosity and grade must be properly maintained during working. Brake pads are actually forced against rotor disc with the help of piston. That piston is moved by brake fluid force which is applied by the brake pedal. 

What is the Difference Between DOT 3 and DOT 4 Brake Fluid?

DOT means the department of transportation. It gives some properties and characteristics to brake fluid manufacturers that every manufacturer should be aware of. 

1 – Boiling Capacity

DOT 3 is comfortable and performs well with wet boiling capacity. This brake fluid becomes more useful when it comes in contact with moisture or air.

DOT 4 brake fluid is comfortable with dry boiling capacity. It should not be in contact with moisture. The wet boiling capacity of DOT 4 is low. 

2 – Boiling Point

The boiling point of DOT 4 brake fluid is higher than DOT 3 brake fluid. Heavy braking generates more heat so brake fluid also got higher temperatures. Brake fluid should sustain at higher heat. It doesn’t get boiled easily. In this condition, DOT 4 is good fluid. 

3 – Mixture of Chemical Compositions

Ether and poly glycols, these two chemicals are used to make DOT 3 brake fluid Whereas DOT 4 brake fluid is made from borate and glycol. Every time it is not essential that brake fluid making with this or that chemicals.

Every manufacturer makes some changes in chemicals or their percentages in compositions. These changes give different properties and characteristics to brake fluid according to required operating conditions.

4 – Manufacturer type of car 

Nowadays, car manufacturers are putting conditions on brake fluid use according to car type and required braking force. DOT 3 is used for average braking conditions where the compulsive brake is not in use. 

On the other, powerful cars require sudden braking therefore brake fluid used should be compatible with higher temperatures. For such cars, DOT 4 is recommended.

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