A hydraulic brake system must be well-lubricated and without air bubbles and dirt that degrade the braking effect. The brakes are a key component of the car as well-maintained and well-functioning brakes ensure your safety while you navigate through traffic.
When you press the brake pedal, the brake fluid puts pressure on the brakes on each wheel through the brake caliper in each "corner" of the car. It puts pressure on the brake pads which in turn presses against the brake discs (or drum), after which the speed of the wheels is lowered or stopped completely if the pressure continues..
Over a certain amount of time dirt, water and air bubbles can get into the hydraulic fluid and it breaks down the fluid. In addition, condensed water can get into the fluid, through which it slowly loses its effect - which is an increased risk when the driver is braking hard. If you need to replace the brake fluid in your car, you wil see the brake fluid symbol light up in the dashboard: The brake light.
When you have the brake fluid changed, the mechanic will use a break fluid tester to measure the boiling point. Then he will pump out the soiled fluid until it is no longer brown or dirty and then refill the tank with completely new fluid.
How often should you change brake fluid?
If it has been a long time since you have replaced your car's brake fluid, a complete brake fluid change will ensure that your brakes work perfectly again. The weather in Northern Europe can be tough on most cars, so a routine check of the brakes is a really good idea - especially in regard to your safety and the safety of the people around you. So how often to change brake fluid?
Depending on the type of brake fluid you use, you should change the brake fluid every year or second year. DOT 3 and 4 lasts around this long, before you need to refill. DOT 5 lasts longer, however.
You should check your car's brake fluid on a yearly basis or every two years, but check your service manual for how often your car and model needs it.
There are two kinds of tasks related to the brake fluid: Replacing it - the brake fluid is completely removed and gets refilled - or in relation to a service inspection where the brake fluid gets checked and then new fluid gets added.
As stated above new brake fluid mainly just gets added when you need to change your brakes or during a service check. It takes a few minutes for the mechanic to fill it up with new brake fluid.
There is also a difference in the brands of the hydraulic fluid. However, the brake fluid DOT 4 does not cost more than £10 for one liter, while other liquids can be cheaper or more expensive. Check your service manual for the optimal guidance for your car.
In general, the brake fluid change cost is around £40, which includes brake fluid and one hour at the workshop. Use Autobutler to get 3 quotes for the job, so you can get an overview.
If you, on the other hand, find that there might be a break fluid leak, either from the brakes, you should have the car's brakes checked instead as something could be wring with the calipers, hoses or cylinders.
Brake fluid is classified by the abbreviation DOT which stands for Department of Transport.
As already described above, the brake fluid is responsible for transmitting the braking force from the pedal to the wheel brakes. In this process, the brake fluid acts as a transfer medium, which is why the following requirements apply to it:
The United States Department of Transportation (DOT) defined 116 different brake fluid requirements, which determined 4 different types of brake fluid, which are commercially available on the market. So if you're asking yourself "What brake fluid do i need?", take a look here:
Brake fluid DOT 4 lasts longer than DOT 3, as it does not absorb water as easily as DOT 3 and in that way maintains a higher boiling point for a longer period of time - up to 2 years. DOT 5.1 also has a high boiling point, and it lasts even longer than DOT 3 and 4.
The biggest benefit with DOT 5 is that it lasts for many years, especially if you do not drive much (driving in cities). It costs almost twice as much as DOT 4, however. You should also be aware that DOT 5 isn’t as sensitive as the other 3 types of fluids when it comes to pressure; that means braking will fell more “spongy” and soft with DOT 5!
Generally, the brake fluid should be changed according to the manufacturer's instructions. This information can be found in the service book of your car. Most vehicle manufacturers prescribe the first brake fluid change after 2 years, regardless of driving performance and mileage. From this point on, the amount of water in the brake fluid increases, causing bubbles to appear in the fluid at elevated temperatures and the boiling point decreases. When braking, these gas bubbles burst, which reduces the brake pressure.
If you bring your car to the brake fluid change in the garage, the mechanic first measures the water content. If the water content of the brake fluid is above 3.5 percent, it must be replaced. Therefore, it is important to have your car checked regularly so that the water content is not exceeded. The brake fluid symbol for a pending change is a warning light in the dashboard of your car which indicates if there are any problems with the brakes. When the red call sign lights up in a circle, it is time to replace the brake fluid. An additional indication can also be grinding noises, which are noticeable while braking.
It is a good idea to have your brake fluid replaced during the service inspection because the inspection intervals are the same. If you are keeping your car properly maintained, you should take it to a garage for a check up regularly. Therefore it is recommended to have the brake fluid changed at the same time, so that you do not have to worry about when the fluid was last changed and how often it has to be changed. In addition, the brake fluid control is part of the maintenance work anyway and it can be replaced directly in case of a low level.
The loss of brake fluid or even a brake fluid leak can be amplified by porous brake lines and seals as well as leaking connections. Therefore, it is particularly important to have the brake fluid level checked regularly with the increasing age of your car. You can also check the level of brake fluid yourself and do not have to drive to the garage.
It is best to check the brake fluid level on a flat surface while the engine should be cold. In the first step you open the bonnet and check the brake fluid level in the reservoir. Most vehicles have a transparent reservoir with visible minimum and maximum marks. The markings indicate whether the brake fluid level is optimal or whether the brake fluid should be changed. If not, you can use a brake fluid tester to measure the level and the boiling point of the fluid.
Some older cars have a metal container in the engine compartment instead of a transparent one. To read the brake fluid level, simply unscrew the cap and read the fluid level using the markings in the reservoir. If the level is below the minimum, you can additionally check the brake discs. If you can see grooves on the brake discs, then you should go to the garage and have the brake fluid changed.