How to Change Brake Fluid in a Car How to Change Brake Fluid in a Car
Knowing how to change brake fluid can mean the difference between a mushy brake pedal that goes right to the floor when depressed and a firm, well-functioning brake system. Changing the brake fluid in your car’s brake system is different than adding fresh brake fluid to it. Adding brake fluid simply requires you to locate the brake master cylinder, remove the lid and pour in fresh fluid. Changing it, on the other hand, requires that you bleed the brake system.
Remove the Brake Fluid
With a helper ready, have a brake bleeder kit and a small socket set. Locate the wheel cylinder valve on the backside of each wheel housing. Open the valve with the socket, attach a long plastic tube to the end, the other end of which is in an empty container. Have your helper pump the brakes until all of the fluid is ejected from the cylinder and only air comes out. Tighten the valve before the helper lifts their foot off the pedal. Repeat this for the other three wheels. In this way, all the brake should be ejected from the system.
Refill Master Cylinder and Bleed the Brakes
Refill the master cylinder with brake fluid then set about bleeding the brakes. Do this the same way as with the removal, except you now want to expel all of the air from the lines. Open each valve and attach the tube with the other end in a container filled with brake fluid. Tell the helper to pump the brakes until the bubbles stop coming into the container. Tighten the valve, release the pedal and repeat for the other wheels. Keep refilling the master cylinder before you bleed each wheel.
Once all four wheels have been bled of excess air, refill the master cylinder one last time. The brake fluid in your car has been successfully replaced.