How to Adjust Hydraulic Disc Brakes on a Bike

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Undoubtedly, there is a reason why hydraulic disc brakes are increasingly becoming popular.

Unlike the traditional rim brakes, disc brakes have remarkable stopping power in mud, rain, and snow. Also, the hydraulic disc brakes can be used with any tire width.

And because they use the fluid as opposed to a cable pulling system, hydraulic disc brakes tend to offer fast and efficient braking.

However, like any other brake type, once installed, you`ll need to adjust them accordingly to ensure they`re set up properly and to your riding preference.

In this article, we shall explore everything you need to know how to adjust your hydraulic disc brakes on your bike.

Step 1: Mount Your Bike

First off, mount your bike on a stand. This will make the disc brake adjustment an easy affair.

 Step 2 : Check Brake Lever

The next step is to check on the brake lever.

The hydraulic disc brake on many road bicycles is positioned on the handlebar similar to conventional or the non-hydraulic bikes.

We have covered how to adjust other types of bicycle brakes.

When setting the brake lever, ensure that you place it horizontal to the handlebar, within an easy to reach position.

However, according to Telegraph UK, you should avoid tweaking the lever in a crash. Instead, you should rotate it down, and adjust it behind the lever pivot. This is to mean the brake lever should not be level with your handlebar but just below it.

To do this, you`ll need to use a hex wrench to loosen the bolts as you move the brake levers closer to the handlebars and the proper position.

Step 3 : Align The Brake Calipers

The next crucial step after positioning the brake levers is to align the calipers.

It`s essential that your disc brakes have properly aligned calipers, and this will avoid the calipers from hitting the spinning rotor.

Remember that when the caliper hits the spinning rotor, it causes drag and this could impede your performance.

Fortunately, it`s easy to recognize this defect since its often accompanied by a howling or rubbing sound when the caliper alignment is off.

Step 4 : Centering The Rotor

However, for any disc brake system, especially the hydraulic disc braking, it`s difficult to view the pad to rotor alignment.

Therefore, while spinning, ensure that you place a white paper or white rage behind the area of your viewing.

As you spin the wheel, pay focus on how the rotor is spinning in between the calipers.

Ideally, it should be aligned exactly at the center.

In the event you find it rubbing, loosen the two centering bolts that are holding the caliper to the mounting bracket by use of a hex.

If you`re having trouble centering the rotor, you can try slipping a thin business car in between the pads.

Step 5 : Bolt Tightening

Pull the brake lever gradually, and tighten the bolts.

Step 6 : Confirm Rotor Is Properly Aligned

To confirm whether the rotor is aligned properly and not rubbing, spin the wheel and the eye disc.

Step 7 : Test Your Bike

The final step is to take your bike for a test spin.

Gradually apply the brakes several times to break the rotors.

Check whether all the braking components are in position and that your bike is braking efficiently.

Common Problems Associated With Hydraulic Disc Brakes And How To Solve Them

Hydraulic brakes have transformed the braking system of bikes. This is because they offer better braking power and reliability. However, just like any other item, you’re bound to encounter a few challenges.

This is especially so if there are poor maintenance practices. We’ll cover common problems encountered with hydraulic brakes and how to overcome them.

Brakes produce a disturbing noise

You may start to hear a metallic sound that may increase in amplitude over time. There are several reasons why this occurs. One, the brake pads may be worn out, misaligned or the brakes are dirty.

Examine the hydraulic brakes to establish the cause of the noise. If the brake pads are less than 3mm in size, it indicates they are worn out and need replacement. If this is done and there’s still noise, check on the alignment. 

Brake pads experience a lot of pressure as they function by coming into contact with a metal surface at a fast pace. They therefore wear out and need regular replacement. Apart from the brake pads, also examine the condition of the rotors. 

Spongy or Loose Brake Lever

If the brakes feel loose and its levers don’t pull as close to the bars, there might be air in the system. Air in the system calls for a bleed.

Bleeding is simply the process of removing air bubbles present in the brake fluid. It may also involve removing old brake fluid and replacing it with new.

So, how does air enter the system? There is no specific mode of entry. When brake fluid is lost when cycling, it’s often replaced by air. Air might also find its way through the brake lines, leaks, joints and diminished seals. 

You may opt to carry out the process of bleeding yourself or use the services of a bike shop mechanic. For doing it yourself, all you need is a bleed kit and mineral oil or DOT brake fluid. 

In the process of bleeding, you may opt to completely remove the brake fluid if it’s dirty, discolored or has water. A common practice is to change the fluid yearly for racers and two years for normal cycling.

Most noteworthy, there are precautions to adhere to when bleeding to avoid causing damage to the brake system.

The most common error that occurs is contamination of other brake parts such as the rotor and brake pad. Handle one section at a time when bleeding the brakes to avoid this.

Other common mistakes in the process include; using the wrong brake fluid and overfilling the brake system. Find out the best brake fluid to use depending on your bike type and use the recommended quantities. 


Aside from contamination of the brake parts using brake fluid during bleeding, there are other ways that this occurs.

Materials such as dust, degreasers, WD-40, grease, oils and other debris may find its way in the hydraulic disc brakes. These materials interfere with the braking system slowing down how fast you can minimize your speed and stop. 

Contamination can be easily prevented by regularly cleaning your bike. This is especially so after cycling in dusty, muddy and wet weather. 

Cleaning your hydraulic brakes needs a little more effort when compared to the other bike sections. Remove the wheel and wipe over the surface of the rotor with a clean cloth until all the visible dirt is transferred to the cloth.

Once this is done, use another piece of cloth with alcohol. This ensures that all the contaminants are dealt with.  

For the brake pads, use a clean cloth, followed by sand paper. Rubbing the pads with sand paper minimizes uneven wearing out.

You should use reasonable force and take a short period of time when rubbing to avoid wearing the brake pads out. 

Misaligned Calipers

In essence, the disc brake calipers need to be aligned over the brake rotors. This ensures that the brake pad and the friction surfaces of the rotor are positioned parallel. 

If not, the rotors will rub on the wheels which will hinder their movement. Moreover, the misalignment may lead to the production of a noisy sound that interferes with your experience.

Follow the procedures described earlier to ensure that the calipers and the entire hydraulic disc brakes system is aligned. 

Breakage of Parts

You’re bound to experience breakages with the hydraulic disc brakes. Due to wear and tear or excessive pressure, they give in and break off beyond repair.

The only solution to this is entirely replacing the part. It’s recommended to have spare parts for quick replacement.

Also, to avoid being caught off-guard when the breakage occurs, make it a habit to always inspect your bike before commencing any cycling trip.

Brakes Not Locking Up

At times, you experience your disc brakes gripping but not locking up. This may be a result of inadequate bleeding, contamination or inadequate connection of the brake lines. 

Check whether all the connections are in order and the system is aligned. If these are in order and locking still doesn’t take place, use the previously detailed measures for contamination and bleeding.    

Stuck pistons

The brake pistons may get stuck and fail to retrack into the caliper as designed. To fix this, you can try to remove and re-fix them.

 If this doesn’t work wash them down to remove any foreign matter that may be stuck. If this also doesn’t work, replace the piston set with a new one. 


Adjusting the hydraulic disc brakes keeps them in good shape for faster and effective braking.

Although these types of brakes offer consistency and reliability especially in wet weather, there are challenges that you’ll encounter. 

Majority of the problems associated with hydraulic disc brakes can be sorted by bleeding, cleaning to remove contaminants and re-aligning the parts. Only extensive damages such as breakage requires complete replacement. 

To keep your disc brakes in check, conduct routine inspections and maintenance practices. 

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