Harley Davidson Rear Brake Troubleshooting

Harley-Davidsons require maintenance just like other bikes and maybe more. One part that you need to be especially careful to maintain is the rear brake. If you suspect you might have an issue, it’s best to troubleshoot and know for sure before hitting the road. As such, in this article, we will explore three steps to troubleshooting Harley Davidson’s rear brake.

Step 1: Apply Consistent Pressure on the Pedal

To troubleshoot a Harley Davidson, apply steady and consistent pressure on the brake pedal. We recommend this first because it helps you know whether or not there is trapped air in the reservoir cylinder. Furthermore, it also enables you to detect a faulty cylinder.

To confirm this, put force on the brake pedal. You may need help if your bike uses a brake with higher technology. One such technology is the ABS brake system.

After you apply pressure, slowly release it to let out the air from the cylinder. If your cylinder has air confined or trapped, you will notice that it is springy and bouncy. In addition, you will also feel a high resistance when you apply the pressure.

On the other hand, several signs also point to a faulty cylinder. One is if you notice that applying pressure on the brake pedal is very difficult. In addition, if the brake pedal sinks to the floor slower than usual or is quite hard, then this means that the cylinder is faulty. 

Step 2: Examine the Level of Force Required to Halt the Bike

The second way to troubleshoot your rear brake is to check the force you apply to make the bike stop or come to a halt. Take it for a spin in your area or a block around you. As you drive, take occasional stops and begin moving again. While doing this, check how much force you had to apply to the power brakes to stop the bike.

You may need to change the bike’s power booster if you put in so much effort in stopping the bike. 

Step 3: Pump the Brake Pedal

The final step in troubleshooting a Harley Davidson is to pump the brake pedal. This is because you need to check the fluid level and confirm if there is a need to reacclimate the brakes.

To do this, pump the brake pedal from a high level. If your bike repeatedly stops, you may need to reacclimate or adjust the brake. This may also mean a problem with the fluid level, so topping up or changing the brake fluid will be a great option.

However, if there is sufficient fluid, you may need to take the bike to an expert for servicing. They will also help to diagnose the problem for better results further.

How to Change Your Harley Davidson Brake Fluid

Brake fluid issues, especially leaking, can cause road casualties if you do not treat the issue as soon as you detect it. In light of this, you should change your brake fluid immediately after realizing it needs the change.

After troubleshooting with step 3, if you notice that you need to change your brake fluid, then you can follow the steps below to do so.

Stabilize the bike and keep it resting horizontally for 15-30 minutes

Open the master cylinder reservoir. You do this by unscrewing the bolts you will find on its covering. In case of doubt, the master cylinder reservoir is commonly known as the brake fluid container.

After that, locate the drain in the receiver to remove trapped air bubbles.

Next, remove the previously used liquid. You do this by installing the pipe on the screw of the reservoir or container. However, be careful not to remove all the fluids and leave a little so air doesn’t get into the container.

After that, use a syringe to insert the new brake fluid into the container.

The next step is to press and free the brake lever. Do this three times.

After that, repeat the previous step once and then hold it. 

Lastly, untwist the screws, and there you have it!


Q1. How can I spot symptoms of rear brake problems?

Some of the symptoms of rear brake problems on your bike may include the following:
a. The bouncy feeling while pushing the brake pedal
b. The brake light constantly on
c. The feeling of swaying, vibrating or scratching while braking
d. Liquid leakage 
e. Metallic noises like screeching and crushing.
f. Releasing smoke when driving

Q2. What are common mechanical problems with a 1980 Harley Davidson Ironhead Sportster?

One common mechanical problem with a 1980 Harley Davidson Ironhead Sportster is that the rear wheel might be shaking. Loose chains or worn-out bearings usually cause this problem. Another common problem is that the engine might be leaking oil. This is usually due to faulty gaskets or seals. Lastly, the carburettor might be dirty, which can cause the engine to run poorly.

Q3. Is there a specific shelf life for brake fluid?

Brake fluids that are sealed often don’t have a set shelf life, but they are suitable for long-term use. However, if you open the container, we advise using it up within a year. This is because the braking fluid’s chemical components begin to degrade when exposed to moisture. Thus, the equation evolves with time. If you use all of it within three months, all the better.

Q4. What could be wrong with a motorcycle whose rear tail lights went out but whose turn signals still work?

There are a few potential reasons your motorcycle’s rear wheel might be shaking or wobbling. It could be that:

a. The chain is loose and needs adjustment. It could also be that the person who did the chain install did it incorrectly.
b. Your motorcycle’s swingarm is bent.
c. The rear tire might be unbalanced or out of alignment.
d. There is an issue with your motorcycle’s bearings or suspension.
e. The spokes are loose. 
f. Bearings are worn out. 
g. Finally, it is also possible that the tires are not properly inflated.
h. If your motorcycle’s rear wheel is shaking, it is best to take it to a mechanic to check it.

Q5. How can I check the brake fluid level of the rear brake on my Harley bike?

You can inspect the fluid level of the rear brake using the sight glass at the rear of the master cylinder reservoir.

a. Removing the cap at the top of the reservoir is crucial before carrying out significant scheduled maintenance. This makes it possible to see the fluid level, and it also makes it possible to condition it more clearly.
b. After major maintenance, you should often clean, replace or drain the Harley braking fluid. It is nevertheless crucial to have a good understanding of the brake fluid condition at these services. 
c. If the fluid is leaking or the cylinder is wearing out, having this understanding will help you spot the initial signs. Always remember that the foot brake pedal at the rear end is close to the reservoir of the rear cylinder.
d. Detach the top cover and its seal. When detaching the top cover and its seal, proceed with extreme caution. DOT 4 Harley brake fluid may harm leather, painted surfaces, and plastic materials. However, there is no need to panic if DOT 4 brake fluid accidentally gets on a finished surface, but you should act quickly to wipe it up. 
e. With a clean towel and a light glass cleaner, completely wipe it away. Before you open any parts that store or contain DOT 4 brake fluid, it’s wise to get your cleaning tools ready and close at hand.
f. Fasten the top cover with the aid of two Phillips head screws. You can reach these screws most easily with a Phillips screwdriver. This is because a Phillips screwdriver has a longer shank than usual. 

Q6. Is it a cause for concern if the brake pedal touches the floor?

Yes, it is. Even though the cause could be extremely diverse and vary to some extent, you still should address it. The most frequent cause of this is when the brake fluid runs dry. A defective brake booster is another frequent cause of this.

Q7. How do I fix a motorcycle rear wheel that is shaking?

If your Harley Davidson’s rear wheel is shaking, there are a few possible causes. The most common for this is unbalanced tires. You can easily fix this by taking your bike to a tire shop and having them rebalance the wheels. 

Another possible cause is that the spokes on the rear wheel are loose. This is a more serious problem that will require a trip to the mechanic. Lastly, your rear wheel would shake if the bearings were worn out. This is also a serious problem that will require a mechanic’s help.

If your rear wheel is shaking, don’t ignore it. Fixing the problem in time will save you from more serious issues down the road, literally.


Harley Davidsons’ motorcycles are prone to issues just like other bike brands. If you suspect possible Harley Davidson rear brake issues, your best option is to troubleshoot. 

This article has step by step instructions on how to find out the cause of the problem and fix it.