One of the common problems related to brakes is when the brake pedal level is too low. Many car drivers report that after some time, the brake performance changes and is not 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 brake fluid delivery 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 from the bleeding port in the brake caliper, it is an indicator that there is a problem. Ensure that you solve this problem before it results in danger. 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:
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Two people should do this job. It requires one person to press the brake pedal to provide pressure in the brake circuit while the other is bleeding. The brakeman should press the brake pedal as a pulse 5 to 6 times and 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 gets out of 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 might cause the bleed screws to rust or corrode, making it difficult to remove them. The screws can be removed but 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 cut, or it’s torn out, there will be no pressure in the brakes; thus, brake bleeding will fail. It also causes the brake fluid to leak.
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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 coming 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 to one wheel or one caliper won’t bleed, it might be because the caliper’s fault is its sliding pins. The solution is to replace them. Also, check for any leakage in the oil seal of the brake caliper pistons.
If there are no brake fluid pressure rear brakes, check for the pipes that deliver brake fluid to the rear brakes. Sometimes these pipes are exposed to corrosion that makes them have holes and leak the brake fluid. This makes the rear wheels not bleed air and make no pressure on the rear wheels. Therefore check for the leakage spot and, if found, replace the pipes as soon as possible.
If you think that the brake pedal is so light and at the same time there is no brake fluid to a right front caliper/left front caliper, inspect if there is any faulty flex hose that could be torn and get the pressure out of the brake circuit.
How to Bleed the Master Cylinder and Brake System YouTube Video:
Frequently Asked Questions (FAQ)
Q. Can I Change Brake Fluid Without Bleeding?
When getting rid of old brake fluid, you have to bleed it by opening the bleed screws and adding the 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.
Q. Does Engine Need to Be Running to Bleed Brakes?
No, when bleeding the brakes, the engine has to be shut off to prepare a good quantity of pressure before opening the bleed screw. This will not happen when the engine is running.
Q. 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.
Q. 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 some more string presses on the brake pedal to get back the brake’s pressure and make sure that there is no pressure leakage in the brake circuit.
We are now aware of the importance of brake bleeding and how it affects restoring the brake power of the car. It is vital to check the brake components regularly to ensure that there is no leakage or any torn part that may make brakes fail when driving. It is recommendable to get your brakes checked by an expert to ensure that every part is ok and working properly.