Your braking system needs regular changes in order for you to remain safe on the road. You may notice that upon replacing pads or servicing this important aspect of your vehicle, your brake pedal has lost its stiffness and feels somewhat spongy. This is usually a clear indication that you need to figure out how to bleed brakes. Other symptoms may include your pedal dropping too low to the floor when you engage them. When your fluid levels drop too low, air bubbles get trapped in the lines causing the pressure within the system to become inconsistent and lose its strength. To fix this issue you must learn how to bleed brakes. This article will show you the right way to take care of your brake lines and teach you how to bleed brakes after a service.
Things You’ll Need
- A box wrench that fits the bleeder nozzle on your car. There are special bleeder wrenches that are available if you really want the right tool for the job;
- Brake fluid: refer to your vehicle owner’s manual for the proper type used in your specific application;
- Liquid penetrant;
- A turkey baster;
- Lint-free rag;
- A clean container;
- Flexible tubing;
- Another person.
Steps for How to Bleed Brakes
Step 1: The Master Cylinder Reservoir
Locate and remove the master cylinder reservoir. Usually, it is a lighter colored container closed off by a black lid. Often it is in line with your braked pedal in the engine compartment. If you are unable to locate it, refer to your vehicle’s manual.
Step 2: Remove the Old Fluid
Next, you will need to remove as much of the old dirty fluid as you are able. To do so, use the turkey baster to make it easier for yourself.
Step 3: Clean Up
Once you have taken out as much dirty brake fluid as you can get, use the lint-free rag to clean up any sediment left behind. Be sure to avoid getting brake fluid on any painted surfaces. It is corrosive and should quickly be cleaned with some soap and water if it comes into contact with other surfaces.
Step 4: Refill
Using the correct brake fluid for your vehicle, refill the master cylinder and close it off by replacing the lid.
Step 5: Pump it
Engage the brake pedal inside your vehicle and pump it as far down as you can. Do this at least a dozen times.
Step 6: Locate the Bleeder Valve
Somewhere behind each of your brakes, you will find a small nozzle sometimes called a bleeder valve, bleeder screw, or bleeder nozzle. Typically they are about 5/16 of an inch in size. You can jack up your vehicle using jack stands to reach them easier but you should be able to access them from underneath fairly easily. To make it easier on your back, you can use a shop creeper.
Step 7: Using the Wrench
Choose the proper sized box wrench size so that you do not strip the bleeder screw. Doing so will create a tough job that may necessitate needing a professional. It should not take too much force to loosen the screw. If you find the bleeder stuck, use some penetrant to soak it for an hour and attempt to loosen the screw again. You do not need to remove the screw. Be sure to re-tighten the screw lightly.
Step 8: Using the Tubing
Next, you will need the clean container (a jar works well). Then, take the flexible tubing and fit it snugly over the bleeder screw. Fill the jar with clean brake fluid until the other end of the tubing is submerged to avoid the system sucking back any air. The tubing is optional but makes the job much easier and cleaner. If you cannot obtain tubing for the job, simply keep the jar elevated to catch any fluid released during the process.
Step 9: A Buddy Comes in Handy
Have your friend pump the brakes slowly to help build pressure in the system. After several pumps, loosen the screw again to release the air in the lines. If you are using the tubing in a jar, you will physically see bubbles that will help you see how the air disappears from there.
Step 10: No More Air
On the final pump, have your friend hold the pedal down. While in the depressed position, tighten the bleeder screw. Then have your friend release the pedal and loosen the screw again to see if more bubbles show up in the jar of fluid. Repeat this process until there is no more trapped air. You will know it’s gone when the bubbles stop.
Step 11: The Final Step
Once all the air is out and you have repeated the procedure for each of your brakes, you will need to top off the master cylinder with brake fluid. Then start your vehicle and check the tightness of your brake pedal to see if you need to repeat the process or add more brake fluid to the master cylinder reservoir.
Maintaining your brake system to save some money is an easy enough task for garage DIY-ers. Sometimes you may find the need to bleed your brake lines if you lose pressure due to air in your system. If you find your brake pedal to be spongy feeling or that it hits the floor before it wants to stop your vehicle, this may be the case. The process itself is important and will keep you safe on the road. How to bleed brakes is also an easy process to learn and with a little practice, you can do it quickly.