One common problem with brakes is a low brake pedal level. Many car drivers report that, over time, brake performance changes and is no longer the same as when they bought the car. In this case, the mechanic’s first action is to bleed the brake oil to eliminate any air bubbles. This may delay the delivery of brake fluid to the brake caliper. This eventually causes lag in the braking process and lowers the brake pedal level. During this process, you may be surprised that no brake fluid comes out when bleeding. Let us learn the causes of no brake fluid coming out when bleeding and how to fix it.
What Causes No Brake Fluid Coming Out When Bleeding?
If no brake fluid is coming out of the bleeding port in the brake caliper, it indicates a problem. Ensure you solve this problem before it becomes dangerous. Here are the reasons why the brake doesn’t bleed:
Wrong Bleed Procedure
Although it is an easy job, it needs to be done right. When done the wrong way, you will not have any brake fluid coming out when bleeding. The problem might not be in the car but the person bleeding the brake fluid. For a successful bleeding job, follow these steps:
Read Also: The Best Brake Fluid Testers Reviews
Two people should do this job. It requires one person to press the brake pedal to apply pressure to the brake circuit while the other person is bleeding. The brakeman should press the brake pedal in a pulse of 5 to 6 times, then press and hold.
While holding the brake pedal down, locate the bleeding screw. The person bleeding should unscrew the bleeding screw slowly, wait until the oil drains from the bleeding screw, and then tighten the screw.
Check the Dot 3, dot 4 or dot 5, and dot 5.1 brake fluid levels as required in the user manual. If you notice a low level, top up the brake fluid before moving to the next wheel.
This process should be repeated 3/3 times per wheel until no more air is seen.
Bad Bleed Screw
Since brake calipers use brake fluid, the bleed screw is located at the highest point of the brake caliper. It is like a valve for bleeding the air in the brake fluid. The bleed screw is located in the brake caliper behind the wheel. It, therefore, resides in a challenging environment. It is disposed to heat from the braking process, as well as dust and mud from the wheels. This harsh environment may cause the bleed screws to rust or corrode, making them difficult to remove. The screws can be removed, but they can’t bleed because of the blockage in the bleeding passage.
Faulty Brake Flex Hose
Flex hoses deliver brake fluid from the reservoir and brake master/cylinder to the brake caliper. In case the hoses happen to have any cuts or are torn out, there will be no pressure in the brakes; thus, brake bleeding will fail. It also causes the brake fluid to leak.
Read Also: 12 Best Brake Line Flaring Tool Reviews
How to Fix No Brake Fluid Coming Out When Bleeding
To get a proper bleed, stick to the right bleeding process. In case no brake fluid comes from the master cylinder, try to use a proper brake fluid specified for your car model. Also, avoid mixing different types of brake fluids because it might damage your car’s brake system.
If there is no brake fluid in one wheel or one caliper won’t bleed, it might be because the caliper’s sliding pins are faulty. The solution is to replace them. Also, check for any oil seal leaks on the brake caliper pistons.
If there is no brake fluid pressure at the rear brakes, check the pipes that deliver brake fluid to them. Sometimes these pipes are exposed to corrosion, which causes them to develop holes and leak brake fluid. This prevents the rear wheels from bleeding air and prevents them from being put under pressure. Therefore, check for the leakage spot and, if found, replace the pipes as soon as possible.
If you think the brake pedal is so light and, at the same time, there is no brake fluid in the right front caliper/left front caliper, inspect for a faulty flex hose that could be torn and let the pressure out of the brake circuit.
Frequently Asked Questions (FAQs)
Can I Change the Brake Fluid Without Bleeding?
When replacing old brake fluid, you have to bleed it by opening the bleed screws and adding new brake fluid at the same time. Leave the bleed screw open until you find the new brake fluid coming out of the bleed screw. You can differentiate it by its fresh color.
Does the Engine Need to Be Running to Bleed Brakes?
No, when bleeding the brakes, the engine has to be shut off to build up enough pressure before opening the bleed screw. This will not happen when the engine is running.
Can I Mix Old and New Brake Fluid?
Brake fluid is prone to absorbing water. Therefore, it is crucial to change the whole capacity of the brake fluid every two years and put a new brake fluid of the proper type.
Why Are Brakes Still Spongy After Bleeding?
When bleeding, you depress all the pressure in the circuit. After closing the bleed screw, you have to press more pressure on the brake pedal to get back the brake’s pressure and make sure that there is no pressure leakage in the brake circuit.
Final Words:
We are now aware of the importance of brake bleeding and how it affects restoring the car’s braking power. It is vital to check the brake components regularly to ensure there is no leakage or torn parts that could cause the brakes to fail while driving. It is recommended to have your brakes checked by an expert to ensure that every part is in good condition and working properly.
Read More:
Replaced calibers right was sticking now can’t get brake to bleed pump up there times it holds when let go for 5 seconds push back to floor intelligent brake work backing out garage almost hit my truck it stoped itself please help .
76 Corvette. New, not remanufactured master cylinder. No brake fluid at any of the bleeder screws. I did use air pressure to blowout the brake lines. At this point, am thinking using air may have messed up my proportioning valve. Could this be the problem? I have done brake work on many different cars and never had this problem before. Thank you