Harley Davidson Rear Brake Troubleshooting

Troubleshooting brake problems of your Harley bikes

  • Step 1: Put steady pressure on the brake pedal to slowly let the air out of the cylinder. If air is trapped inside the cylinder, you will feel bouncy and resistant when you apply pressure. You can resolve this issue quite easily. If your bike has some sophisticated technology for brake systems like ABS, you can get your friend to help you out with this.
    If you find your brake pedal to be quite firm and difficult to push instead of being resistant, or if it sinks on the floor slowly, it might be caused by a defective cylinder.
  • Step 2: Now, you need to check how much effort you need to put to stop your bike while it’s running. For that, drive around the block and continuously stop and start again. If you happen to have power brakes, your bike should stop 1-1 ½ inches from the floor. Otherwise, it would stop 3 inches from the floor. If you have to put a lot of effort to stop your vehicle, you might need to change the power booster.
  • Step 3: Try pumping the brake pedal from high up. If it makes your bike to stop, again and again, you might need to readjust the brakes or need to put in more brake fluid. If you feel that there is adequate fluid in your bike, you might need to get help from the nearest service provider for further diagnosis.

You can try to check the performance of your bike under the following circumstances as you drive along-
Does your motorcycle need a lot of space when you brake at city traffic? If so, you might need to readjust your brakes or need to replace the brake linings.

If you feel your bike tilts to one side when you push the brakes, it can be caused by a caliper stuck to the brake and any leakage of fluid.

Suppose you find your brake pedal to pulsate up and down, other than in an emergency. It might be a result of overheating of brakes which are caused by overuse.

Harley Davidson Rear Brake Troubleshooting

Harley Davidson Rear Brake Troubleshooting

Changing brake fluid of your bike

As you might have understood by now, that leaking brake fluid might cause disastrous accidents if not handled properly. Before you change the brake fluid, make sure your bike is rested for at least 15-30 minutes. It would help if you kept it stabilized horizontally.

To start with the steps, follow the instructions below-

  • Unscrew the bolts to open the lid of the brake fluid container. It is also called the master cylinder reservoir.
  • Find out the receiver. It has a drain that helps to get rid of the air bubbles.
  • Now, install a pipe on the container screw so that it can extract the used liquid. But make sure you leave a little fluid so that air does not get into the circuit.
  • Inject new brake liquid with the help of a syringe.
  • Squeeze and release the brake lever 3 times. Do this once again and keep it on hold. Then unwind the screws a little.

Flushing brake fluid:

  • Release the brake and let the fluid drain from the pipe slowly. Tighten the screw afterward and then release the handle.
  • Replace the brake fluid as per the instructions mentioned above. Do not let the fluid overflow, exceeding the mark.
  • Finally, screw the lid of the reservoir container.

Bleeding Harley brake lines

If the brake fluid cylinder of your Harley has air trapped inside, it would feel bouncy and spongy when you pedal your brake. You can resolve it by bleeding the valve. For that, you need to remove the rubber cap of the rear brakes’ caliper. Insert the plastic tubing covering the tip of the valve. Place the other end of the tube into a jar.

After that, remove the reservoir cover, use a 4mm socket to unscrew the bolts. Fill the container with DOT 4 brake fluid.
Open the bleed valve using a 9mm wrench turning in a clockwise motion. Push the rear brake pedal and keep on hold. It should flush out the brake fluid through the plastic tube. Be sure to get rid of the air bubbles. Then close the bleed valve counter-clockwise and release the brake pedals afterward.

Now, you need to open the bleed valve again and insert the brake fluid with force. Keep on filling in until the tubing is free of air bubbles.

Close your bleed valve once again in a counter-clockwise motion. Pump your brake pedal slowly to release the air bubble. Then, insert a rubber diaphragm into the cylinder to replace its cover, and finally, screw some bolts with a 4mm socket to set the cover tightly.

Frequently Asked Questions (FAQs)

Why did my brakes suddenly stop working?

This might be termed as a soft brake or sponge brake. Sometimes, when a vehicle’s brake fluid diminishes or the system gets disrupted, it causes the brakes less effective than usual.

What to do to get rid of soft brakes?

If the cylinder of brake fluid is not enough to generate enough pressure to yield maximum braking power, this leads to a soft brake. To solve that issue, you can follow these steps-

  • Pumping the pedal: sometimes air is trapped in the cylinder. By pumping the pedal, you can let that air to exit under pressure, and the brakes can get back to its original state.
  • Finding a leak: this step can help you to find any possible leaks that might have caused the fluid to drain out. This brake fluid keeps the brake in steady condition, saving it from soft brakes.

What brake fluid works well for Harley Davidson bike?

It is recommended to use the DOT 5 brake fluid in your Harley Davidson motorcycle. This is a silicone-based fluid that is very effective and works immediately on your bikes.

Is the brake pedal touching the floor a bad sign?

Yes. Although the reason might vary drastically and it might also vary to certain degrees, it has to be addressed nonetheless. One of the most common reasons for this is when brake fluid runs out. Another common cause for this is a bad brake Booster.

What are the warning signs of a rear brake issue?

Look out for the following symptoms to detect any brake issues-

  • Brake light on
  • Squeaking and grinding noises, and/or metallic noises
  • Wobbling, vibrating or scraping sensation while braking
  • Leaking fluid
  • Soft brakes (spongy, bouncy feeling while pushing brake pedal)
  • Bike leaning to a side while braking
  • Burning fumes while driving
  • Bouncing when you brake

How do I check the rear brake fluid level in my Harley bike?

  • Determining the level of brake fluid in your bike can help you perform the required services for your bike, especially issues like leaking fluid or any other brake issues.
  • It is suggested that you keep some cleaning supplies (cotton rags, glass cleaner, etc.) Nearby if you use DOT 4 fluid for your bike. DOT 4 brake fluid happens to be quite stringent so that it might damage the paint coat, plastic, or leather surface. Thus, you should be able to wipe off the spilling fluid as soon as you uncover the reservoir lid. Now, you need to uncover the top cover with the help of two Philips head screws. You should replace the top cover if it is damaged. DOT 4 brake fluid can be damaging under moisture contact. So, keeping your reservoir lid in the best condition will be beneficial for your bike in the long run.
  • The fluid retention of your brake fluid reservoir will wear down over time. But resist the temptation to fill it to the brim now and then. Ensure adequate fluid to keep the bike in a smooth condition for regular use.

What should be the color of the brake fluid for the motorcycle?

Usually, the color of the brake fluids ranges from yellow to warm amber color. It can sometimes look clear in a new bike, but it will gradually change after some use.

What are the indicators of brake fluid turning bad?

Look for the following clues to determine if your brake fluid needs to be refilled-

  • Dysfunctional brake pads
  • Squeaky, metallic, or any strange noises
  • ABS light comes on; this particular issue indicates if your brake fluid needs a change
  • Burning fumes
  • Pedal problems (soft brake- bouncy, and spongy feeling while pushing brake pedal)

Do brake fluids have any specific shelf-life?

Usually, the sealed brake fluids do not come with a specific shelf-life. These are good to use for a long time. However, if the bottle is opened, it is recommended to finish by 12 months, because when exposed to moisture, the chemical compounds of the brake fluid start to break down. So, the formula changes over time. It is even better if it is used up within 3 months.

Can old brake fluid cause spongy or soft brake?

Yes, sometimes old brake fluid infuses air bubbles which can eventually lead to a delicate brake issue.

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Abdulla Zatar
About Abdulla Zatar

Hi, I’m Abdulla! Your go-to tech troubleshooter! Sharing my knowledge so that you can fix your tech issues with ease. Let’s make fixing things easy and fun!

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