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Do You Have to Bleed Brakes After Changing Pads?

Do You Have to Bleed Brakes After Changing Pads?

A brake pad pushes the discs and facilitates friction to stop a car with brake fluid. Excessive use and heat can damage these pads, which require replacement.

Do You Have to Bleed Brakes After Changing Pads? According to our research, you should bleed brakes after changing pads due to the involvement of the master cylinder and the removal of trapped air bubbles. It helps to remove contaminated fluid and improve the safety of the hydraulic brake system. 

You should remove the fluid from the hydraulic brake system to maintain the stopping force. Clean the fluid lines and protect the system from internal pressure and wear. 

Why do you have to bleed the brakes after changing pads?

You cannot leave the brake lines with trapped air because it affects the car’s performance. Due to the following reasons, it is mandatory to bleed them. 

Involvement of master cylinder

Their bleeding is essential according to the type of techniques that you can use to replace the brake pads. The simplest and most effective method to change them is by using the master cylinder in the procedure.

It involves the master cylinder because the airflow is higher in this equipment. In these conditions, the method starts from the rotors and calipers and uses the master cylinder. 

However, the method is around the cylinders and its valve. Therefore, it increases the chances of airflow inside the valve.

So, you cannot use a similar fluid after changing them. To reduce the damage to pads and other components, several mechanics use the master cylinder. 

In this way, they protect the valve from further damage. However, the other techniques involve the compression of the caliper with a wrench.

It does not involve the master cylinder, and they work efficiently without bleeding. But, it has a long-term effect on their performance and reduces their shelf life. 

Removal of air bubbles

The air bubbles flow inside the flow passages during the pad replacement. Due to an open valve, oxygen can enter the system and trap in the narrow passages. 

As a result, the pads undergo severe pressurized conditions. As a result, they cannot push the discs due to insufficient force. Moreover, the hydraulically controlled pistons extend more than the standard length. 

Then, they push the pad on the disc to generate the braking force. Due to this internal space, the air can move inside the system. 

During its replacement, more air enters and traps inside the flow lines. In these conditions, you should remove the entrapped air from the passages through bleeding. 

Moreover, air can undergo compression, which reduces the internal pressure and braking force. Therefore, replacing old fluid with new is an efficient technique to remove the bubbles. 

In these conditions, its removal is essential because the abundance of air can make the brakes rigid. Moreover, it reduces control over the vehicle and results in life-threatening events. 

Remove the contaminated fluid

The fluid gets dirty due to dirt particles that enter the system from external air. In addition, the airflow inside the hydraulic system can cause the accumulation of dust inside the fluid. 

In these conditions, the contaminated fluid cannot perform braking. In addition, due to dirt particles, the air can oxidize the brake fluid. 

As a result, it reduces its performance at different temperatures. The boiling point of the liquid reduces from the standard limit.

In addition, moisture flow can cause steam and water droplets in the liquid. The dirt combines with the water droplets and produces crystalline particles.

These tiny particles reduce the efficiency of brakes. In addition, the pedal becomes slow when you do not bleed the brakes after swapping pads. 

With the bleeding procedure, you can remove the contaminated and thick fluid from the system. Replace it with clean liquid and improve the brake efficiency. 

Improve safety

The pads, flow lines, master cylinders, and calipers are essential components of a hydraulic system. They protect the vehicle from sudden rolling due to their internal force and pressure.

During the pad swap, the airflow can affect the hydraulic pressure. It reduces from the standard range and causes internal resistance. 

The pads do not push the discs, which affects the stopping force. In these conditions, bleeding is necessary because it improves hydraulic pressure. 

Moreover, it stabilizes the performance of discs and makes them effective. In these circumstances, the brakes can stop the vehicle in emergencies without resistance. 

What are the different ways to bleed brakes after changing pads?

You can bleed them after swapping the pads with the following methods. Use a manual technique to drain the old and contaminated liquid from their lines. 

Adjust a pan under the bleeder and untighten the screw. Take the help of a friend to press and release the pedals with general movements. 

The pressure can pump the fluid out of the system. Keep the movements slow to reduce the airflow. You can add the new liquid through the valve of the master cylinder.

 Moreover, you can use the natural gravitational force to drain the hose completely. For this procedure, adjust a bucket under the bleeder, loosen the screws and allow the gravitational flow of liquid in the bucket.

With his method, you cannot collect the fluid with a straight line technique. Also, you can use a vacuum cleaner to remove the fluid from the system.

In this method, clean the screw and attach it with a vacuum. It is a bleeder which can pull the liquid and oxygen from the valve.

During drainage, you can collect it in a plastic bucket.

Put a pan under the screw and adjust a pressurized fluid with the master cylinder. It can push the lubricant and entrapped oxygen from the equipment. 

You can use a technique according to convenience and remove the dirty fluid. After this removal, add more fluid in the master cylinder and leave it to flow to the flow passages. 

What happens if you don’t bleed your brakes after changing pads?

You cannot leave the brakes without bleeding after the pads replacement because it reduces the car’s efficiency.

Moreover, the airflow is higher than the standard levels during these swaps, which produces internal compression, and reduces their hydraulic pressure. 

In these conditions, you cannot stop the vehicle before the stop. In such circumstances, sudden vehicle rolling and uncontrollable speeds are common problems. 

Non-bleeding conditions can reduce the pad’s efficiency, results in wear, and reduces its shelf life. In addition, the new brake pads cannot last long due to air and contamination inside the cylinder. 

You should not drive a car without brake bleeding because it leads to sudden crashes. Furthermore, the collisions are severe, which causes vehicle damage and life loss. 

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