How to Gravity Bleed Brakes Alone

Maybe you just want to bleed your brakes because you changed your pads, changed your rotors, and just want to get the air bubbles out. Maybe you’re like me and you changed not only the caliper but also the brake line. In any case, the whole point of bleeding your brakes is to get the air out of the system and that’s what we’re going to do now to bleed your brakes on your own.

In this article, I will show you how to bleed your brakes by gravity alone. Gravity bleeding is a process in which the brake lines are manipulated to remove trapped air bubbles. Gravity bleeding is an effective method of releasing air bubbles contained in the brake lines and the result of this process is always 10/10.

Gravity Bleed Brakes

Gravity Bleeding is a method in which new fluid is introduced into the system while the old fluid is drained. The idea is that the incoming fluid expels any air bubbles that may form.

As you probably know, the brake fluid needs to be changed approximately every 2 years, because brake fluid draws moisture from the air. If the brake system is heavily loaded from long and prolonged driving, it heats up and the heat is transferred from the brake pads to the brake pistons and from there to the brake fluid. The water contained in the brake fluid begins to boil much earlier than the pure fluid would.

This process produces vapor bubbles, which cause longer pedal travel and a reduced braking effect.

This happens because the water in the brake fluid is compressed in the brake lines. The driver can determine this very quickly because the brake pedal feels very “spongy” at this point and can be depressed without any braking effect.

Can I Do Gravity Bleed Brakes Alone?

If you don’t have a helping hand, you can still bleed the brakes in most cases.

So, yes, for this, you just need to open your bleeder and let gravity do its job.

Tools Do I Need To Bleed Brakes:

  • Masking tape for the safety issue
  • A small pair of vise grips
  • An open-end wrench
  • An empty quart jar
  • One quart brake fluid/ oil
  • 5 feet of 3/16-inch plastic tubing
  • Automotive jack and four jack stands
  • Hammer

How to Gravity Bleed Brakes Alone

If you proceed carefully, you can bleed the brake system yourself. However, if you are in any doubt, it is best to leave it to the professional. After all, brake failure can quickly lead to an accident with damage to the sheet metal and, in the worst case, injury.

The top priority is cleaning in the form of lint- and dirt-free gloves and rags so that no foreign bodies can enter the brake system and cause damage. Therefore, the separation points must be hermetically sealed immediately after each work step.

Step 1: Raise Your Vehicle above the Ground

First, you need to raise your car. Make sure the car is secure before working on it. If you shake it slightly, you can see if it is holding steady. Do not push too hard if the car is not stable, as the jack could slip and the car could be damaged. When the car has been raised and is standing securely, you must remove the wheels. Use the wrench for this.

Step 2: Find The Brake Fluid Reservoir

Find and remove the top of the master cylinder reservoir. As a general rule, cars have this reservoir which is light-colored with a black cap. It is located in line with the brake pedal in the engine compartment.

Step 3: Attach The Plastic Tubing

You will need to start with the brakes that are located furthest from the master brake cylinder. These are usually the right rear brakes. Locate the brake line bleeder screw and slide the end of clear tubing over the screw nipple.

Dip the other end of the tubing into a container that is held above the fluid reservoir. This will prevent air from being sucked into the brake system.

Step 4: Release the Air Bubbles

Loosen the bleed nipple screw with the wrench approximately ¼ turn. While the hose is still attached, loosen the bleed screw. This opens the brake line and allows the fluid to flow.

Since the brake fluid reservoir is higher than the bleeder screws, gravity may cause a small amount of fluid to flow into the hose when the bleeder screw is opened. This is a good sign that there are no obstructions in the fluid line. This process will take about 3 to 4 minutes, so you will need to be patient.

To speed up the gravity bleed process, take a wooden handle or a rubber mallet and tap the brake calipers several times. Check your brake fluid reservoir, it should be properly filled.

Step 5: Close The Bleeder And Replenish Brake Fluid Reservoir

Close the bleeder. Before removing the clear tube, close the vent screw to prevent air from entering. The bleeder screw does not need much force to close. A quick tug should be sufficient. Brake fluid will come out of the hose and you will have a rag ready.

Check the brake fluid level in the reservoir. You will see that the level has dropped a little. Add more brake fluid to refill the reservoir. Do not let the brake fluid reservoir run dry.

If there are air bubbles in the previous fluid, repeat the above steps until the fluid is clean and clear.

Step 6: Bleed The Remaining Brakes

Repeat this process for each other brake valve until all four are fully vented. Make sure the amount of brake fluid in the reservoir does not drop below ¼ cup, as this could cause air to enter the brake system.

Step 7: Test Drive And Troubleshooting

It’s time for a test drive. Step firmly on the brake pedal to make sure it is nice and firm before starting the vehicle. At this point, it should feel almost like stepping on a rock.

You may feel the pedal go up or down as the vehicle starts and the power assist starts. This is normal as the brake booster system amplifies the force you apply with your foot and transfers it through the hydraulics. Take the vehicle for a drive and slow down with a firm application of the brake pedal to test its work. The brakes should have a very quick and sharp response to your pedal applications. If you feel that the pedal is still too quiet or the braking power is insufficient, you should ask a local expert for help.

What Is There to Bleed?

Since this is a DIY car repair, you can bleed the brakes on your own. Its main purpose is to remove air bubbles from the brake fluid in part or all of the brake lines, depending on the situation. Only by removing the brake fluid from all four wheels of the car can this trapped air being released.

Some people are puzzled about how air bubbles get stuck in the brake line. At first glance, this seems odd, since brake lines are intended to provide an excellent seal. Air, on the other hand, has the ability to infiltrate tiny areas unexpectedly.

It is possible for air to enter your car during repairs, maintenance, and other routine checks. If there is a leak in the system, it has the potential to seep into the brake line and cause damage. If the wheel brake pads are old and worn, air can sneak into the braking system.

In either case, the only method to eliminate air trapped in the braking system is to bleed the brakes completely. Before performing this procedure, the brake fluid must be drained. Brake fluid is a medium in which air bubbles are trapped, and must be drained first.

Why Is There a Need to Bleed the Brakes?

You should bleed your brakes because air trapped in the brake line increases the likelihood of a catastrophic car accident.

How can you tell if your car’s brake system has trapped air?

If you notice a soft brake pedal or a reduction in braking ability, air trapped in the brake system may be the source of the problem. Since your life is in danger, this is an emergency that should be taken care of as soon as possible. Driving a car with bad brakes endangers you, other drivers, pedestrians, and motorists on the road.

As a safety precaution, you should bleed your vehicle’s brakes regularly, not just when the brake pedal becomes loose. It is advisable to perform preventive maintenance activities every two to three years.

It is also recommended to bleed the brakes every 20,000 kilometers. This process should also be followed every time the brake pads, hoses, or calipers are checked or changed by a professional. This rule should always be followed if you want to avoid a traffic accident.

Consequently, you should bleed your brakes regularly while you continue to drive your car. In the long run, you will accumulate thousands of miles if you keep driving your car. A small amount of air will enter the brake line as a result of this movement and will get stuck there over time. When you step on the brakes, if there is enough air trapped in the system, you will feel a spongy sensation.

All fluids in the car, including brake fluid, should be inspected regularly. The most essential safety feature is your car’s brakes. Only when the brake fluid is in excellent condition can the brake function properly. When air is trapped in the brake fluid, it fails. It will be a colossal failure in its function.

What causes air to enter the brake line?

The brake fluid in your vehicle is hygroscopic, which means it accumulates moisture. This implies that this fluid has the ability to absorb moisture from the air. When water binds to this fluid, it substantially lowers its boiling point.

When the oil reaches its boiling point, the water will come out as vapor from the brake pipe. Due to the small amount of fluid flowing through the brake pipe, your brake pedal will feel like a sponge. You will also see black gunk build up in the brake fluid reservoir over time. This gunk is caustic and, if not removed quickly, can cause more air to enter the braking system. If you don’t fix it right away, your brakes can be ruined.


FAQs

When should I bleed the clutch?

The moment the clutch sticks or when you cannot engage the gears correctly.

How does air get into the clutch?

Actually, no air should enter the clutch system. However, if a line or a master or slave cylinder is leaking, air can enter the system.

What to watch for when bleeding a clutch?

Since air has entered the clutch system through a leak, the leak must first be found and sealed. Only then can the air be removed. When draining the brake fluid, you should also make sure that it ends up in a container, if possible, and not in the tires, as it is aggressive and can damage the rubber.

Final Thoughts – Gravity Bleeding Brakes

Gravity bleeding the brakes is accomplished by removing the master cylinder plug and allowing all of the brake fluid to bleed into the gravity drain pan. This will allow air bubbles trapped in the brake line to escape.

To effectively release brake fluid, it is usually necessary to remove the wheel cylinder or caliper furthest from the master cylinder. Use the cylinder opposite the engine first, then the left front cylinder, and finally the right front cylinder.

Things to consider

Brake fluid is a hazardous chemical and should be handled with care. Therefore, it is imperative that you wear gloves when bleeding the brakes and that you wash your skin and clothing thoroughly if you have come in contact with the product. When it comes to brake fluid, always read the label first and follow the instructions carefully.

If you have a safety problem, you should go to a shop to bleed the brakes. Once you have bled the brakes, it is important to test them afterward. If something seems to be wrong, or if you feel that the brakes are weaker than before, you should not try to solve the problem yourself unless you are absolutely sure what the problem is.

Liam

Hi, I'm the initiator and writer of this blog. Cars were and will be my first love, and my favorite hobby, that's why I decided to start this blog and write about my discoveries and techniques to improve my cars or repair them.