There’s nothing more frustrating than being out on a ride and having your rear brake fail. Not only is it dangerous, but it can also be a major inconvenience. If you’re experiencing this issue, you’re not alone. Rear brake failure is a common problem, but it’s one that can be easily fixed. In this guide, I’ll walk you through the steps to troubleshoot and repair a rear brake that’s not working. By the end of this guide, you’ll be back on your bike and enjoying the ride again.
Why Mountain Bike Rear Brake Not Working
Brake Pads Worn Out
The most common reason for a rear brake not working is that the brake pads are worn out. When the brake pads are worn out, they no longer have enough material to make contact with the rotor and slow the wheel down.
To check if the brake pads are worn out, you can look at them and see if they are thin or if the metal backing is exposed. You can also try to squeeze the brake lever and see if the pads make contact with the rotor.
If the brake pads are worn out, you will need to replace them.
Brake Caliper Not Adjusted Properly
Another common reason for a rear brake not working is that the brake caliper is not adjusted properly. When the brake caliper is not adjusted properly, the brake pads may not be able to make contact with the rotor, or they may not be able to apply enough pressure to slow the wheel down.
To check if the brake caliper is adjusted properly, you can look at it and see if the brake pads are aligned with the rotor. You can also try to squeeze the brake lever and see if the pads make contact with the rotor.
If the brake caliper is not adjusted properly, you will need to adjust it.
Brake Fluid Leaking
A third common reason for a rear brake not working is that the brake fluid is leaking. When the brake fluid leaks, it reduces the pressure in the brake system and makes it difficult for the brake pads to apply enough pressure to slow the wheel down.
To check if the brake fluid is leaking, you can look under the bike and see if there is any fluid on the ground. You can also try to squeeze the brake lever and see if any fluid comes out of the caliper.
If the brake fluid is leaking, you will need to have it repaired or replaced.
Brake Hose Clogged
A fourth common reason for a rear brake not working is that the brake hose is clogged. When the brake hose is clogged, it prevents the brake fluid from flowing properly and makes it difficult for the brake pads to apply enough pressure to slow the wheel down.
To check if the brake hose is clogged, you can try to squeeze the brake lever and see if the pads make contact with the rotor. You can also try to blow through the brake hose to see if you can clear any obstructions.
If the brake hose is clogged, you will need to have it replaced.
Brake Lever Not Working Properly
A fifth common reason for a rear brake not working is that the brake lever is not working properly. When the brake lever is not working properly, it may not be able to generate enough pressure to apply the brake pads to the rotor.
To check if the brake lever is working properly, you can try to squeeze it and see if it moves the brake caliper. You can also try to hear if the brake lever makes a clicking noise when you squeeze it.
If the brake lever is not working properly, you will need to have it repaired or replaced.
How to Troubleshoot: Mountain Bike Rear Brake Not Working
Symptoms
There are a few different symptoms that may indicate that your mountain bike rear brake is not working properly. These include:
The brake lever feels spongy or does not return to its original position after being squeezed.
The brake pads do not make contact with the rim when the brake lever is squeezed.
The bike slows down slowly when the brake lever is squeezed.
The brake makes a squealing or grinding noise when the brake lever is squeezed.
Causes
There are a number of different things that could cause your mountain bike rear brake to not work properly. These include:
Dirty or worn brake pads:
If the brake pads are dirty or worn, they will not be able to make proper contact with the rim and will not be able to slow the bike down effectively.
Incorrectly adjusted brake cable:
If the brake cable is not properly adjusted, it will not be able to apply enough pressure to the brake pads and will not be able to slow the bike down effectively.
Clogged brake hose:
If the brake hose is clogged with dirt or debris, it will restrict the flow of brake fluid and will not be able to apply enough pressure to the brake pads.
Damaged brake caliper:
If the brake caliper is damaged, it will not be able to apply enough pressure to the brake pads and will not be able to slow the bike down effectively.
Troubleshooting
To troubleshoot a mountain bike rear brake that is not working properly, you will need to first identify the cause of the problem. Once you have identified the cause, you can then take the necessary steps to fix the problem.
Step 1: Check the brake pads
The first step is to check the brake pads to see if they are dirty or worn. If the brake pads are dirty, you can clean them with a clean rag and some rubbing alcohol. If the brake pads are worn, you will need to replace them.
Step 2: Check the brake cable
The next step is to check the brake cable to see if it is properly adjusted. To do this, you will need to loosen the cable clamp bolt and then adjust the cable until there is about 1/8 of an inch of free play in the brake lever.
Step 3: Check the brake hose
The next step is to check the brake hose to see if it is clogged. To do this, you will need to disconnect the brake hose from the brake caliper and then blow through the hose. If you can feel air coming out of the hose, then the hose is not clogged. If you cannot feel air coming out of the hose, then the hose is clogged and will need to be replaced.
Step 4: Check the brake caliper
The final step is to check the brake caliper to see if it is damaged. To do this, you will need to inspect the caliper for any cracks or damage. If you see any cracks or damage, then the caliper will need to be replaced.
How to Fix a Mountain Bike Rear Brake That Is Not Working
Once you have identified the cause of the problem, you can then take the necessary steps to fix the problem.
To fix dirty or worn brake pads:
1. Remove the brake pads from the brake caliper.
2. Clean the brake pads with a clean rag and some rubbing alcohol.
3. Replace the brake pads if they are worn.
To fix an incorrectly adjusted brake cable:
1. Loosen the cable clamp bolt.
2. Adjust the cable until there is about 1/8 of an inch of free play in the brake lever.
3. Tighten the cable clamp bolt.
To fix a clogged brake hose:
1. Disconnect the brake hose from the brake caliper.
2. Blow through the hose.
3. If you can feel air coming out of the hose, then the hose is not clogged. If you cannot feel air coming out of the hose, then the hose is clogged and will need to be replaced.
To fix a damaged brake caliper:
1. Remove the brake caliper from the bike.
2. Inspect the caliper for any cracks or damage.
3. If you see any cracks or damage, then the caliper will need to be replaced.
Conclusion
By following these steps, you can troubleshoot and fix a mountain bike rear brake that is not working properly. If you are unable to fix the problem yourself, you can take your bike to a qualified bicycle mechanic for assistance
FAQs: Mountain Bike Rear Brake Not Working
Why is my mountain bike rear brake not working?
There are a few possible reasons why your mountain bike rear brake may not be working.
The brake pads are worn out: This is the most common cause of a rear brake not working. When the brake pads wear down, they no longer make contact with the rotor and cannot slow the wheel down.
The brake cable is stretched or frayed: A stretched or frayed brake cable can cause the brakes to feel spongy or unresponsive.
The brake fluid is low or contaminated: If the brake fluid level is low, the brakes will not have enough pressure to slow the wheel down. If the brake fluid is contaminated, it can cause the brakes to become sticky or ineffective.
The brake caliper is misaligned: If the brake caliper is not aligned properly, the brake pads will not make contact with the rotor evenly and the brakes will not work properly.
The brake master cylinder is leaking: If the brake master cylinder is leaking, the brake fluid will not be able to reach the brake calipers and the brakes will not work.
How do I fix my mountain bike rear brake?
To fix your mountain bike rear brake, you will need to identify the cause of the problem and then take the appropriate steps to fix it.
If the brake pads are worn out, you will need to replace them: To do this, you will need to remove the brake pads from the caliper, install new brake pads, and then adjust the brake calipers.
If the brake cable is stretched or frayed, you will need to replace it: To do this, you will need to remove the old brake cable, install a new brake cable, and then adjust the brake levers.
If the brake fluid is low or contaminated, you will need to bleed the brakes: To do this, you will need to remove the brake calipers, remove the old brake fluid, and then add new brake fluid.
If the brake caliper is misaligned, you will need to realign it: To do this, you will need to loosen the bolts that hold the brake caliper in place, adjust the caliper so that it is aligned properly, and then tighten the bolts.
If the brake master cylinder is leaking, you will need to replace it: To do this, you will need to remove the old brake master cylinder, install a new brake master cylinder, and then bleed the brakes.
How can I prevent my mountain bike rear brake from failing?
There are a few things you can do to prevent your mountain bike rear brake from failing.
Regularly inspect your brakes for wear and tear: Check the brake pads for wear, the brake cable for fraying, and the brake fluid level for contamination.
Bleed your brakes regularly: This will help to remove any air bubbles that may have formed in the brake lines and will ensure that the brakes are working properly.
Be careful not to apply too much pressure to the brake levers: This can cause the brake pads to wear out prematurely and can also damage the brake calipers.
Wear a helmet and other protective gear when riding your mountain bike: This will help to protect you in the event of a crash.
What are the signs of a mountain bike rear brake failure?
There are a few signs that your mountain bike rear brake may be failing.
The brakes feel spongy or unresponsive: This is a sign that the brake pads are worn out or that the brake fluid level is low.
The brakes make a squealing or grinding noise: This is a sign that the brake pads are worn out or that the brake caliper is misaligned.
The brakes are not slowing the bike down as quickly as they used to: This is a sign that the brake pads are worn out or that the brake fluid level is low.
The brakes are leaking brake fluid: This is a sign that the brake master cylinder is leaking.
What should I do if my mountain bike rear brake fails?
If your mountain bike rear brake fails, you should stop riding your bike immediately and take it to a bike shop for repairs. You should not attempt to ride your bike with a failed rear brake, as this could be dangerous.
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