Change brake fluid
Brakes are essential for any car and this makes brake fluid one of your car's most important components. Brake fluids resist the moisture that can cause vapour lock brake failure, protect against corrosion, and withstand high brake temperatures. Every so often you need to change brake fluid in line with your car manufacturer’s manual. You may also need a second person to help you.
There are 6 steps in our how to replace brake fluid guide. This quick guide is intended to help you to understand the process. Changing brake fluid isn’t a do-it-yourself task except for the very proficient as it requires some professional training and modern braking systems work at extremely high pressures. You should check your car manufacturer’s manual to see if any repairs to the braking system are legally permitted other than at an authorised workshop.
1)Drain the old fluid
Find the brake master cylinder, remove its cap and drain off as much of the fluid as possible. The best way to tackle this is with the car up on axle stands, with all four wheels removed.
2)Change brake fluid
Fill the master cylinder right up to the FULL line with new brake fluid.
3)Flush the calipers/wheel cylinders
Release the bleed nipple at the back of each brake calliper/wheel cylinder to drain the old brake fluid.
4)Bleed the brakes
Go to each caliper/wheel cylinder in turn and open the bleed nipple to complete the brake fluid change draining out the last of the old fluid and any air bubbles until the new fluid comes through.
5)Top-up
Keep checking the level of brake fluid in the master cylinder and keep it topped up.
6)Repeat the process
Bleed each caliper/wheel cylinder in turn until you have worked your way through all of them.
Whenever you change brake fluid or someone does it on your behalf, dispose of the old oil in an environmentally friendly manner. There are different rules for ASR (traction control), ESP, SBC and hybrid / electric propulsion cars and you should check these out before disposing of used fluid.
How long does it take to change brake fluids?
A skilled mechanic will be able to carry out a brake oil change in 30 to 60 minutes.
Brake flushing machines
Some workshops use brake flushing machines. Brake flushing machines eliminate the need for a second technician and include a pressure regulator and gauge to set proper fluid pressure.
Castrol React Performance DOT 4 brake fluid
Castrol Dot 4 brake fluid is liquid engineered to prevent vapour lock and protect your brake system. To find out more about Castrol’s brake fluids.
