A lack of brake fluid being expelled during bleeding is typically a result of subpar procedures or a faulty bleed screw. Issues like defective brake calipers, insufficient brake fluid, and the accumulation of corrosion can also lead to this problem.
Experts and vehicle manufacturers recommend changing your vehicle’s brake fluid at least every two to five years, depending on your car. The rule of thumb is to change the fluid every time the mechanic does any oil changes. Maintenance and regular repair schedules are some of the measures that will ensure you do not experience any brake fluid coming out when bleeding.
This article will take you through the brake fluid bleeding basics and why the procedure is essential. We will dive into the various causes that will prevent brake fluid bleeding and share a few FAQs to answer your burning questions. Read more to find out what is affecting your vehicle’s brake fluid.
What is the brake fluid?
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Brake fluid is a crucial part of your hydraulic braking system. It is a liquid chemical that is housed in the braking system lines. Its purpose is to amplify the force you put on the brake pedal and transmits that force at higher pressures to the vehicle’s brakes. The fluid is non-compressible, allowing it to transmit the amplified force without a hitch.
Different vehicles use different brake fluids depending on the viscosity and base of the fluids. The proper brake fluid for your engine is generally indicated on the owner’s manual, but you can visit your local mechanic for further clarification. It is important to note that you need to use the correct brake fluid for your vehicle.
Most brake fluids are glycol-or silicone-based, which helps standardize the products. The two types are never mixed since their properties are different; mixing them will cause brake fluid bleeding issues and general brake system failures.
Recommendation:
Bosch ESI6-32N Brake Fluid
Prestone AS400 DOT 3 Synthetic
Lucas Oil 10826 Brake Fluid
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What should I do if no brake fluid comes out when bleeding in my car?
The first thing you want to do when you notice no brake fluid comes out when bleeding in your car is to take note of the bleeding procedure. We dive into the proper bleeding procedures in one of the topics below, be sure to check it out. Once you notice the correct procedure is being used, you can note a few things.
One of the things to note is where the problem is occurring. You may find that the bleeding occurs perfectly on one wheel or one caliper but fails on another, especially the rear wheels and calipers. Note where the problem arises and keep other car faults in mind, like caliper malfunctions.
It is also essential to take note of the brake fluid your vehicle uses. If you did not use the suitable braking fluid for your car, the problem might arise. Mixing two different types of brake fluid can also result in no brake fluid coming out when bleeding.
Do not proceed to drive your vehicle in this condition. Brake fluid and brake system failures are dangerous problems that can lead to disastrous consequences on the road. Feel free to visit your local mechanic shop if you are unfamiliar with fixing common brake issues. Ensure you have a partner to help you fix the problems, as the process can be tedious and impossible for one person to do.
The causes and how to fix it
The issues that can cause no brake fluid to come out when bleeding is vast. It is crucial to follow through with each diagnosis not to miss any underlying problems. Below are some common causes that will result in no brake fluid coming out of your braking system.
1. Wrong methods of brake bleeding procedure
The various methods used to bleed the brake fluid require two people, but one person can perform some. The most common way is the pump and holds technique, where two people are needed. All you need to do for this process is have one person press on the brake pedal with the foot, and the other person opens the bleed screws.
The bleed screws have to be opened one at a time to ensure the air escapes. A good rule of thumb is to have the brake pedal individually press the pedal on a pulse of five to six while holding in between the intervals.
Wrong bleeding procedures are the most common cause of this issue. So, how do you fix the problem?
How to identify and solution: step by step
- Use the proper procedure by checking in with the equipment and manpower.
- Go through the options and note the procedures you can apply, such as the pump and hold method, pressure method, vacuum method, reverse method, and gravity method.
- Pick one of the procedures, in this case, the pump and hold method.
- Start with one individual pressing the brake pedal at the stated intervals (five to six) while holding in between.
- Let the other individual bleed one screw at a time, slowly. Tighten the screw once the oil gets out.
- Proceed to look at the Dot 3/Dot 4/Dot5 & Dot 5.1 of the brake fluid levels. This helps you notice the levels of the brake fluid. Top up if the levels are lower than the recommended amount on the owner’s manual.
- Repeat the process three times to ensure no air is retained in the system.
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2. Bad bleed screws
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The brake screw, which is located on the brake caliper fluid chamber exterior, is used to open up the bleeding lines for brake fluid bleeding. You can see them on the brake cylinders of each wheel. These screws are located in a harsh environment, making them prone to wear and corrosion malfunctions. The major causes of these failures include moisture, a lot of heat from the calipers, and road salts during winter.
Once the bleed screws go wrong, your vehicle may start experiencing other issues like brake fluid leaks, blockage in the system, and general corrosion around the area. Previous repairs on the system can also cause damage to the bleed screws in a mistake case.
How to identify and solution: step by step
- Start by visually locating and inspecting the bleed screws in your vehicle. Pay attention to any signs of corrosion and wear.
- Once you locate the wrong bleed screws, note if they are blocked or wholly damaged.
- Remove any blockage that can be taken out and replace the part if it has gone bad. This should solve the bleeding issue if there are no other causes.
3. Faulty flex hose
Flex hoses are located in the front and rear of the vehicle to transmit brake fluid from the brake fluid reservoir to the brake cylinder and calipers. These hoses are also located in places exposed to the harsh environment outside. This makes them prone to faults through corrosion, blockages, and rots.
How to identify and solution: step by step
- Visually inspect the flex hoses around the area that cannot bleed brake fluid. Take note of any corrosions, rust, and internal wall damage. There may be leaks due to a cut on the hoses.
- Go ahead and press the brake pedal to apply pressure to the brake fluid. A bulge in the flex hoses will let you know there is a blockage.
- Proceed to replace the flex hoses in case there is a leak, a blockage, or the parts have become rotten and rusted.
4. Malfunctioning brake caliper
Brake calipers experience a lot of issues like faulty pins that seize as well as pistons. Other problems include sliding brake caliper pins and seals that leak. This issue is most prevalent in old vehicles that commonly experience seized pins from exposure to the moisture, which is then absorbed into the pins, causing corrosion.
Incorrectly fitted brake calipers will prevent you from bleeding the brake fluid because the air bubbles accumulate in the system.
How to identify and solution: step by step
- Ensure to note if the right and left side calipers are placed in the correct positions. The bleed screws are located on a correctly placed brake caliper towards the top. This ensures air bubbles are not trapped in the hoses as air tends to flow towards the highest points.
- Go ahead and change the calipers to their correct position if they are incorrectly placed.
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5. Low brake fluid level
Low brake fluid levels can cause the issue since there isn’t enough fluid to go through the brake system. The owner’s manual indicates how much brake fluid levels need to be at any particular point in your vehicle.
How to identify and solution: step by step
- Check the fluid level in the reservoir and compare it to the owner’s manual recommendation.
- Proceed to top up the system with the correct braking fluid if the issue lies here.
Recommendation:
Bosch ESI6-32N Brake Fluid
Prestone AS400 DOT 3 Synthetic
Lucas Oil 10826 Brake Fluid
6. A lot of air in the system
As noted earlier, air bubbles can prevent brake fluid from bleeding. The idea behind this is that air affects the compressibility of the brake fluid. More pressure is required to compress the air in the system, which affects the fluid bleeding process.
How to identify and solution: step by step
- Press the brake pedal and notice the amount of pressure used to bleed the fluid.
- If the pressure is more than the usual amount, there may be air bubbles in the system.
- The pump and hold method may be tedious to fix this issue so ensure to use the pressure method or the vacuum method to get rid of the fluid.
- Ensure there are no air bubbles once you have bled the system to prevent the issue’s reoccurrence.
7. Blocked/Leaking Pipe
As previously discussed, the pipes can leak and get blocked due to exposure to harsh environments. Do not be alarmed about this issue since it is common in many vehicles. The blockage or leak can also happen due to inclusions in the brake fluid, or due to the use of the wrong type of fluid.
How to identify and solution: step by step
- Ensure you use the correct type of braking fluid. The wrong type may cause blockage. Take note of the kind of fluid – if it needs to be changed for the one recommended by your manufacturer.
- Press on the brake pedal and note what happens to the pipes. A bulge represents a blockage, and a lack of bleeding points to a leak that can be noticeable.
- Proceed to replace the faulty pipes.
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8. Corrosion buildup
The entire brake system is located in a very exposed environment. Corrosion buildup is inevitable as the vehicle ages, so it is essential to plan for this problem in the future. The issues may include corrosion on pipes, bores, calipers, and discs. The point that causes brake fluid not to bleed is corrosion on the lines or the bores of the brake fluid system.
How to identify and solution: step by step
- Visually inspect the brake fluid bores and pipes for any signs of corrosion.
- Proceed to replace the entire parts since they are causing the bleeding issue or will cause the problem eventually.
How much will it cost if I fix it?
The cost of fixing this problem depends on the causes. You can expect to spend between $80 and $100 for simple issues like not using the right procedure, bad bleed screws, and hoses. However, extensive causes like corrosion on brake cylinders and calipers can cost you between $320 and $500.
Conclusion
The first step to fixing the bleeding issue is to use the correct procedure. Bad bleed screws, faulty flex hose, and malfunctioning brake caliper are other common causes that can lead to the problem in most vehicles. Ensure to have someone help you in bleeding the fluid brake or take the car to your local mechanic for further issues.
FAQs
- Do you open the brake fluid reservoir when bleeding?
The brake fluid reservoir should be unscrewed, but the cap should remain on top when bleeding the brake fluid.
- How much fluid should come out when bleeding brakes?
The brake fluid should not be bleed more than 3 inches. You can bleed one inch for a small procedure and a maximum of 3 inches for a complete fluid bleed.
- Do I need to bleed all 4 brakes?
All four brakes need to be bled in the proper sequence, as indicated in the owner’s manual. A general rule is to start with the brake farthest from the master cylinder. Ensure to check in with your vehicle’s specific process.
- Do you bleed brakes with the cap on or off?
The cap should remain on top of the reservoir and not wholly unscrewed. This helps in the bleeding process.
- Can you damage the master cylinder when bleeding brakes?
The master cylinder can damage brake bleeding if you press the brake pedal to the floor. The component usually damaged by this is the piston seals in the master cylinder due to the pressure.
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