No Brake Fluid Coming Out When Bleeding: What Causes It?

If no brake fluid comes out when bleeding, some common causes can occur such as a damaged master cylinder, clogged brake hose or line, clogged duct, and damaged balance valve.

So there are many different causes of this condition. If you want to learn more about the main causes as well as how to effectively fix problems related to brake fluid, follow the article below.

No Brake Fluid Coming Out When Bleeding: 6 Basic Causes

As you know, before determining an effective remedy, you need to understand some of the common causes of brake fluid problems. Here are 6 basic causes and remedies to help you handle this situation correctly and quickly.

Clogged Bleed Valve

First, check the bleeding valve because it could be the main cause of this condition. Normally, we often tend to maintain or replace brake pads, and brake discs. As a result, the internal brake system is often less serviceable and less hygienic. As a result, debris and contaminants often lurk inside the brake system.

In particular, if the bleed valve does not have a rubber cover to prevent dust and debris, it will quickly cause damage to the brake system. If you have identified the cause of the bleed valve, you can take some of the solutions below.

How to fix

  • You should prepare some necessary tools such as brake cleaner, metal debris remover, hose cleaning brush, and wrench set. Some steps you can take to check and fix are as follows:
  • Remove the bleed valve from the brake caliper. Then you need to check if the brake fluid is draining from the brake pads.
  • If the liquid starts to flow from the brake calipers, you will need to clean the bleed valve.
  • You need to spray brake cleaner through both holes, top, and bottom. At the same time, you need to carefully clean the inside with a pipe-cleaning brush.
  • If you’ve sprayed brake cleaners to no avail, you should soak them completely in brake cleaner for 10 to 25 minutes.
  • Repeat the cleaning process until the brake cleaner drains into the bleed valve.

The Brake Caliper Is Clogged

Another common cause of brake fluid is a clogged brake caliper. You can discover this cause while driving. In addition, debris or small pieces of metal can also enter the caliper from the master cylinder. As a result, the brake hose may become clogged and the oil cannot drain out.

How to fix

  • You need to prepare some necessary tools for testing such as a wrench set, WD40, and air compressor. Follow the steps below to check the brake calipers.
  • You need to remove the brake hose to check if it’s the brake caliper.
  • The part of the tube that is attached to the brake caliper is a metal tube. Please avoid bending or breaking it. You should spray some rust remover on it first.
  • After removing the brake caliper, you need to check to see if the oil is draining out of the hose.
  • If oil is leaking out of the hose, blow some compressed air into the caliper and see if it works. Alternatively, you can remove the valve to get a flow of air through the hose. If the oil still won’t drain, continue reading for the causes below.

Clogged Brake Lines

Clogged brake lines can also result from dirt and metal debris getting into the hose and clogging the brake hose. You still need to prepare a wrench, air compressor, and WD40. The steps you need to follow are the steps below.

How to fix

  • Remove the brake hoses carefully and do not break them.
  • Once removed, open the brake fluid tank cap and blow some compressed air into the brake line. You should blow a short stream of air to remove debris and debris from the hose. Because if you blow a lot of air into the brake hose, it takes a lot of work to push that air out as well.
  • If you blow air through the brake hose and the oil is still not coming out, the cause may be the metal part of the line has collapsed due to rust or check for the next cause.

Brake Line Leak

Broken or leaking brake lines are also the cause of the oil not flowing out. You may think that this test is very simple because you can see it with the naked eye. However, the holes in the brake lines can be so small that they are invisible to the naked eye. In particular, the brake lines are almost as long as the car’s length and there are many wires everywhere. Therefore, checking the brake lines will also take a lot of your time.

How to fix

  • You need to carefully inspect each brake line on your car to look for holes or holes. You should check each brake line from the master cylinder to the corresponding wheel.
  • You need to look carefully and can use a clean cloth to wipe and more easily detect cracks.
  • If you find any hoses, brake lines, or hoses broke, replace them for safe driving.

Bad Proportioning Valve

If you find that the brake fluid is not draining from the rear or front wheels, the proportioning valve may be stuck or damaged. The purpose of the proportioning valve is to distribute brake pressure between the front and rear axles. In addition, it will transmit more pressure or braking force to the front wheels.

If the proportioning valve detects a loss of brake fluid pressure on one of the axles, it understands that there is a leak on that shaft and shuts down the function to avoid wasting brake fluid.

This problem can occur when you try to use the brake. When you step on the brake and release the pressure by opening the valves, you simulate the loss of pressure on that shaft. So you can check the proportioning valve and reinstall it or if it doesn’t work you should replace it.

How to fix

  • You need to prepare some tools as follows double-end flare nut wrench and socket wrench set.
  • Locate the proportioning valve. It is usually located on the firewall or the brake lines from the master cylinder.
  • Then you remove all brake lines from the proportioning valve. Try to be careful not to bend or break them.
  • Remove the bolts holding the valve to the firewall.
  • Install a new proportioning valve and reattach all brake lines to their original positions.
  • Tighten them by hand and then use a double-end flare nut wrench.

Faulty Master Cylinder

Brake fluid not draining can also be related to the master cylinder. If the cause is the master cylinder, you will have the brake fluid in the reservoir bubbling every time you depress the brake pedal. However, the air can come from other places. So you need to check if there are any broken or leaking brake lines. In addition, you also need to check for signs of brake fluid coming out of the caliper or valve.

How to fix

  • Check for broken or leaking brake lines. Signs of brake fluid leak in the caliper or the proportioning valve.
  • If you find no signs of a leak and the brake fluid is bubbling in the reservoir, you should replace the brake cylinder.


No brake fluid coming out when bleeding can result from many different causes. Some common causes include clogged bleed valves, clogged brake clamps, clogged brake lines, leaking brake lines, bad proportioning valves, and faulty master cylinders.

You can look for cracks or leaky brake lines, brake hoses can be clogged with dirt or metal debris for days. Therefore, to ensure that the brake fluid can move, you should clean and periodically maintain parts such as brake lines, brake hoses, cylinders, or valves.

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