INSPECTING AND CHANGING BRAKE PADS ON A HARLEY SPORTSTER
Your brake pads are very important inspect and replace when needed. Worn out brake pads are a safety hazard should you need to stop fast when out riding. Conveniently, changing your own Harley brake pads is an inexpensive and easy task you can take on yourself. In the video below, we show you how!
WATCH VIDEO: INSPECT & CHANGE HARLEY FRONT BRAKE PADS
Steve Knoble of Knoble Moto walks you through how easy it is to visually inspect your front brake pads. He also shows how to remove and replace them on a 2012 Harley-Davidson Sportster. The inspection and replacement process is the same on many different years and models.
HOW TO CHANGE YOUR HARLEY BRAKE PADS IN 5 EASY STEPS
These two bolts hold on your caliper.
STEP 1: REMOVE THE BRAKE CALIPER & BRAKE PADS FOR INSPECTION
First thing, loosen and remove the two bolts that are holding on the caliper with a 10mm 12 point socket or wrench.
Remove the two bolts holding the caliper and slide it off of the rotor, be careful and don't allow the caliper to fall down and pull on your brake line.
Once the caliper is free from the bike, remove the flat head set screw cap that keeps the brake pad pin in place.
You can see after the flat head cap was removed there is a hex head. Removing this hex head pin will allow you to separate the brake pads from the caliper.
Be sure to hold your brake pads when removing so they don't fall out.
This is what the friction material looks like that you will be inspecting on the brake pads.
STEP 2: VISUALLY INSPECT YOUR BRAKE PADS
The area you want to inspect is the raised, coarse material that makes contact with the brake rotor. If your pads are .040 of an inch or less it's time to change your brake pads.
A good way to check if you don't have a caliper handy is measure your brake pad thickness with a dime, which is .050 of an inch.
Holding a dime up to the backing plate can help you measure the friction material on your break pads and determine if it is time to change them or not. This one in the photo has lots of meat left and should be good to go for a while.
If your brake pad friction material is at or less then the thickness of a dime, its time to change those bad boys!
These pistons inside the caliper are what press your brake pads onto the rotor.
STEP 3: COMPRESS THE PISTONS BACK INTO THE CALIPER
The pistons are 'pucks' that push the brake pads against the rotor when you apply the brakes. As time passes, and your brake pads get thinner, the pistons take up more and more of the slop.
These pistons must be compressed back into the caliper before installing the new brake pads or the caliper will not fit over the rotor properly.
You can use a c-clamp or a skinny flat piece of metal bar or even your old brake pad. You can use anything that can fit inside the caliper and lay over the pistons to help you compress them back into the caliper.
Using a c-clamp you can put the end on both pistons and compress slowly, it doesn't take a ton of force. Watch them compress down and become flush with the wall of the caliper, don't over do it.
STEP 4: INSTALL THE NEW BRAKE PADS
Make sure the friction material is facing on the inside of the caliper, so it will contact the surface of your brake rotor.
Also check that the holes are in the proper position to engage the locking pin.
Make sure to inspect the little spring on the end of the caliper. That spring keeps tension on the brake pads and if they are loose or bad can cause your brake pads to squeal.
Here is the location of the spring that keeps tension on the brake pads.
Again the friction material goes on the inside of the caliper. Notice the tang on the top of the pad, that goes on the right and the hole goes on the left of the caliper. Same with the second one. The friction material goes on the inside, the tang to the right and the hole to the left.
Holding the brake pads open with your one thumb while inserting the pin can help locate the pin in each hole easily. Tighten. You don't have to crank it down excessively.
Reinstall the flat head cap on top of the pin.
Here is the location of where the flat head cap goes.
STEP 5: REINSTALL THE BRAKE CALIPER
Slide the caliper over the rotor and reinstall the two bolts into the lower fork leg. tighten down both then torque to factory recommended specification.
If your caliper isn't sliding on to the rotor easily, you need recheck your pistons are pushed in all the way in you caliper.
Torque to factory specifications stated in your workshop manual. You have a workshop manual for your bike, right?
Marking your caliper bolts at 12 O'clock is just a reassurance on making sure your bolts stay in the same place
Pump those front brakes up until the handlebar lever gets hard. Before you go for a ride, hold your front brake and try and push your bike and forth to make sure they are properly working.
Last thing you want to do is find out the pistons weren't compressed all the way and you flew through a stop sign trying to stop.
You are now ready to go for a ride!
PRO TIP: CLOCKING YOUR BOLTS FOR SAFETY
Mark your caliper bolts at 12 o'clock with a paint marker or marker. This gives you a quick visual reference point to check before going for rides. If those dots aren't at 12 o'clock, you have a problem and you want to investigate and re torque those bolts.
Pump up the jams, pump it up, keep on pumpin!
Now you are ready to get out there and ride!
FAQs
Q: What is the difference between sintered and organic (semi-metallic) brake pads, and which is better for a Sportster?
A: Organic (semi-metallic) pads are softer compounds made from rubber, glass, and metal fibers. They are quieter, gentler on rotors, and perform well in normal street conditions — the right choice for most Sportster riders. Sintered (metallic) pads contain a higher concentration of metal particles bonded by heat and pressure. They handle higher heat better, work well in wet conditions, and last longer, but generate more rotor wear and can feel grabby until warmed up. For a Sportster used as a daily rider or custom street machine, sintered pads offer the best overall performance. For a show bike ridden occasionally, organic pads are fine.
Q: How often should Harley Sportster brake fluid be changed, and what type is required?
A: Harley-Davidson recommends changing brake fluid every two years regardless of mileage. Brake fluid is hygroscopic — it absorbs moisture from the air over time, which lowers its boiling point and can lead to brake fade under hard use. Sportsters from 1986 onward use DOT 4 brake fluid. Never mix DOT 3 and DOT 4 fluids, and never use DOT 5 silicone fluid in a system designed for glycol-based DOT 4 — the two are incompatible and mixing them will destroy seals and compromise brake performance.
Q: How do I know if my Sportster's brake rotor needs to be replaced at the same time as the pads?
A: Inspect the rotor surface when the pads are out. Three signs it needs replacement: visible grooves or scoring deeper than surface scratches (run a fingernail across the surface — if it catches in a groove, the rotor needs replacing); thickness below the minimum spec stamped on the rotor edge (usually around 3.5mm for stock Sportster rotors); or heat discoloration with a blue or purple tint over a wide area, which indicates the rotor has been overheated and may have warped. A rotor that is grooved and a new set of pads is a poor combination — the new pads will wear into the grooves immediately.
Q: My Harley Sportster caliper piston won't compress back into the bore — what does this mean?
A: A piston that resists compression despite firm, even pressure from a c-clamp typically indicates a seized piston due to corrosion or debris in the bore. Before condemning the caliper, ensure you are applying pressure evenly across the full piston face and that the brake fluid reservoir cap is loose (allowing fluid to flow back as the piston retracts). If the piston still won't move, the caliper needs to be rebuilt or replaced — forcing a seized piston risks cracking the caliper bore or pushing the piston at an angle, which damages the seal. A caliper rebuild kit is inexpensive compared to replacing the entire caliper.
Q: Is the brake pad replacement process the same on the rear brake of a Sportster as on the front?
A: The same fundamental process applies — remove caliper bolts, slide off caliper, remove old pads, compress pistons, install new pads, reinstall. However, the rear caliper on a Sportster is typically a single-piston design (the front uses a dual-piston caliper), making rear piston compression simpler. The rear caliper is also mounted differently — on the swingarm or hardtail rather than the fork leg — so access and the direction you need to work from differ. Consult the factory service manual for your specific model year to confirm rear caliper bolt size and torque spec, as these differ from front caliper specs.
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