Diagnosing common problems with motorcycle disc brake systems.

Disc brakes are a fairly common braking system on motorcycles today because of the many advantages they offer over other types of brakes. Therefore, while motorcycles previously used drum brakes for both wheels, nowadays most motorcycles on the market use disc brakes for the front wheel and drum brakes for the rear wheel, or disc brakes for both the front and rear wheels.

While disc brakes are considered to have many advantages such as precise braking and short braking periods, they are also prone to malfunctions that can impair braking accuracy. What's concerning is that most people pay little, or even no, attention to these issues until they encounter problems on the road.

Here are some common problems with motorcycle disc brake systems:

1. The brakes make a loud noise when applied.

This is a very common problem; everything is fine when driving normally, but when you apply the brakes, they make a loud noise, much louder than usual, and you can even hear the sound of metal scraping against each other.

If you hear a loud noise when you apply the brakes, it could be due to worn brake pads.

Reason:Worn brake pads cause the brake disc to collide with the brake pad frame, resulting in loud noises and even rendering the brakes ineffective.

How to handle itNaturally, the only solution in this case is to replace the brake pads immediately to avoid scratching the brake discs.

2. When pushing the bike without using the brakes, a squeaking sound appears in the brake area.

This is a fairly common problem, occurring in most vehicles using disc brakes. It's when riding, or even pushing a motorcycle without using the brakes, that you hear a squeaking or grinding sound.

I was pushing the motorbike and not using the brakes, but I heard a squeaking sound coming from it.

ReasonBecause the disc brakes are located in an exposed position, they are easily exposed to dust, dirt, and water during driving. Alternatively, a warped or bent brake disc could cause friction between certain parts of the disc and the brake pads, resulting in squeaking noises.

How to handle it:To fix this, you should spray a strong stream of water to wash away the sand and mud from the brake system, then dry it. This should resolve the issue. If the brake disc is bent, you will need to replace the entire brake system on your motorcycle.

3. The brake is stuck to the brake disc and cannot be released.

This is what happens when you've been driving for a long time and suddenly one day you find the brakes sticking, even when you're not pressing them. You can't find a way to loosen the brakes to make the car go faster.

Worn brake pads and calipers will also cause the brakes to malfunction.

Cause: The brake fluid has run out or has been inactive for too long, preventing the piston from pushing properly, and consequently, the brake pads stick to the brake disc.

How to handle it:In cases involving brake fluid, the motorcycle's brake fluid needs to be replaced. You should have a mechanic drain all the old brake fluid from the reservoir before adding new fluid.

4. The brakes are sticking, and the braking feel is unresponsive.

This is the phenomenon where, while driving, you feel the brakes are stiff, causing the car to slow down, and when you apply the brakes, you don't feel a firm grip.

The brake seals, both the upper and lower pistons, are worn out due to prolonged use, causing the dust and oil seals to swell.

Cause: The brake disc is warped. You can visually inspect it by putting the bike on its center stand, pressing down on the rear wheel so the front wheel doesn't touch the ground, then manually rotating the wheel and observing. It's advisable to replace warped brake discs to protect the brake pads, clutch, and save fuel.

Brakes are seized.

The dust and oil seals on both the upper and lower pistons swell due to prolonged use or water ingress into the brake fluid, causing the pistons to seize. A weak return spring fails to push the brake lever back to its original position, preventing the brake fluid from returning. Pitted brake pistons also make the brakes prone to seizing, leading to brake binding.

Poor quality brake pads, combined with continuous braking while driving (especially downhill), can cause the brake pads and discs to overheat and stick together, leading to brake seizure.

How to handle it:Depending on the cause, you can find appropriate solutions, specifically: Replace the brake disc if it is warped; Clean the dust seals; Replace the brake caliper springs; Replace the piston system; Replace with higher quality brake pads.