Replacing and Maintaining Motorcycle Brakes
We all focus so much on how fast our ride goes, but sometimes it's important to take a
moment to check how well your motorcycle can stop. Braking on a motorcycle can be
just as important as accelerating. You'll want to make sure that you're properly
maintaining your brakes as well as replacing them when they need to go. Of course, as
always, every bike model is different so be sure to check your service manual for more
information.
Brake Types
It wouldn't be any fun if all brakes were the same. So instead, we've outlined different
types of brakes that your bike may have. The main two categories are drum brakes and
disc brakes.
Drum brakes have been around a lot longer but have a tendency to have more issues.
Mostly found today on smaller bikes, drum brakes work by pushing shoes up against the
inside of a drum in order to cause friction to slow the motorcycle down. In order to spot
this type of brake, you'll be able to notice a "drum" mounted on the wheel of your
motorcycle. If you can't seem to find this drum because it is either internal or combined
with the rim of your bike, you'll just have to look for a brake disk. If there isn't one, your
brake system operates off of a brake drum.
Disc brakes are a lot easier to work with as they are less likely to overheat and need less
up-keep than drum brakes. You can easily spot these types of brakes by taking a gander
at your wheel and spotting a metal disc full of holes in it that is significantly smaller than the
circumference of the wheel itself. If you have an older bike, your brake disk may not
have the holes as many early brake disks were solid. Disc brakes can operate on both the
front and rear wheels by using a system of pistons that are housed inside calipers which
press the pads against the disc you spotted by your wheels. Motorcycles can have these
types of brakes on both the front and the rear on some models, while others may only
have them on the front wheel with drum brakes on the rear.
Of course, nothing is ever perfect and because disc brakes are not protected by the drum,
they're more subject to the elements. In wet weather, disc brakes leave pads to be
exposed which can cause the pads to work a little less effectively. While this doesn't
mean you can't ride in all conditions, it's always a good idea just to keep this is mind if
you happen to get caught riding in the rain. And while disc brakes typically need less
care, both drum and disc brakes require regular maintenance in order to work properly.
Braking for Maintenance
Waiting for your brakes to fail before you get around to checking them for wear and tear
will not only end badly for your bike but will end badly for you as well. Failing brakes
are one the worst and most dangerous of bike problems and can happen at the most inopportune of
moments. In order to keep your brakes from failing miserably right when you need them
to work desperately, be sure to check them often. And while you could have a mechanic
check them every now and then, it's not only cheaper to do it yourself, it'll also help you
keep those stoppers in the best condition possible.
The first thing you will always want to do when checking your brakes is to check how
thick the brake pads are. Even the best of brakes will wear down over time and need replacing. You
don't want to wait until your brakes are gone and it's actually the metal backing of the
pad and not the pad material that's slowing you down. If you let your brakes get that low,
it'll damage your brake discs and require you to change them out which will cost you
precious ride time and a pretty penny. Instead, change your brake pads at the first sign
that they're getting a little too low.
Changing your Brake Pads
If your brake pads are in need of a replacement, no amount of maintenance will keep you
from having to make the switch. Changing out your brakes is just a way of motorcycle
life. Brake pads should be replaced once they've gotten down to 1/8 of an inch of
thickness unless your owner's manual says otherwise. Some brake pads will have wear
indicators that will show you when they need to be changed but can show unevenly.
Change out your brakes when one pad reaches the indicator even if the other isn't quite
there yet. Luckily, this procedure is fairly simple and won't require the most skillful
motorcycle surgeon to be done correctly.
Locate the caliper that is attached to the rotor on your wheel. Before detaching the
caliper, if there is a bolt holding the pads in place loosen it but don't remove it
completely. Once it's loose, unscrew the bolts that are holding the caliper in place on the
rotor and carefully slide it free. If you've dumped quite a bit of cash for those shiny rims
of yours, be sure not to let the caliper bump your rim as it may scratch it.
As the pads wear down, the pistons inside the caliper that push the pads onto the disc in
order to stop your bike adjust slightly with them. Since there is less padding between the
pistons and the disc, the pistons will have been pressed out of the caliper a little more
than when the pads were first installed. Because of this, you'll need to push the pistons
back into the caliper as much as possible in order to give the new pads enough room. Any
easy way to do this is to insert a flathead screwdriver in between the pads before you
remove them from the caliper and gently wiggle it so that the pads get pushed back
further into the caliper and the pistons reset. Another way to do this is by pushing the
pistons back into place with your thumb after removing the pads but this way requires a
bit of thumb strength.
Once the caliper is free from the disc and your pistons are pushed back, remove the pin
that is holding the pads in place completely. This pin is long but should come free fairly
easily if you loosened it before removing the caliper as mentioned before. Some of these
pins will be held in place by tiny copper pins. If yours is, remove these pins with needle
nose pliers first. Once the pin is out, there may be a retainer spring plate laying on top of
the pads which will come right out and then allow you to slide out the brake pads. Some
bikes will also have insulators or spacers that will go behind the brake pads in order to
make the brakes quieter and reduce vibrations. These are often optional and can either be
replaced or removed depending on your bike.
Now you can put the new brake pads into place, put the spring plate (if your bike had one
in the first place) back over them and insert the pin back into the caliper. If you removed
tiny copper pins, be sure to put them back in place as well. You may find it to be easier to
apply a tad bit of grease to the pin before screwing it back in. Now that the caliper is all
put back together, slide it back onto the rotor. If it doesn't seem to fit back on the rotor,
this is probably because you didn't push the pistons back far enough and you may have to
remove the new pads in order to push the pistons far enough back into the caliper to
allow enough room between the new pads for the rotor. After you get the caliper back in
place, add some blue lock tight to the bolts that hold the caliper in place and reattach
them to the rotor. It's never a bad idea to check your service manual as it may
recommend tightening the bolts to a specific torque.
You may think that's the end of your brake pad replacement process, but there's still one
important and final step before you can hop on your bike and expect your brakes to keep
you from screaming bloody murder as you fly down a hill at top speeds without being
able to slow down. Right after you've finished the install, pump the brakes several times
in order to make sure that they are back in their proper position. You'll then want to
check the brake manufacturer for their recommended "bed in" procedure. It's important
to bed in your brake pads to a clean rotor in order to prevent glazing and allow for the
pads to mate properly with the rotor's surface. One standard way of doing this is to ride
slowly at about 10-15 mph and do gradual and periodic stops. Increase the speed at which
you stop at by 10 mph each time until you're going about 40-50 mph. Do this about two
or three times to allow the brake pads to break in. After that, just remember to be
particularly careful with your braking on your first ride out.
More of a visual learner? Here's a vid from the guys over at Galfer on how to swap out sportbike brake pads:
Bleeding Brakes
No matter how new your brake pads are, a huge part of disc brake maintenance is
bleeding the fluid in your brake system. While this may sound like a gory job just by its
name, if done the right way, bleeding your brakes can be a pretty simple job that should
be done at least once a year no matter how often you ride. Brake fluid degrades over time
and will become dark even if you haven't ridden all year long. And since this fluid is
hydroscopic, it sucks moisture out of the air which will cause the performance of your
brakes to deteriorate and make you lose pressure. This problem will increase as your bike
heats up so you may not notice the loss of pressure until you've been riding for a while
and your brakes just stop working and you can't stop. There are a few different
techniques and tools when it comes to bleeding your brakes as with a kit like this
BikeMaster Delux Vacuum Testing and Brake Bleeding Kit or an
air compressor, but we find the most straightforward way to be the old fashion manual
way.
The Manual Method
Since messing with any fluids that are in your bike can be, well, messy, it's always a
good idea to make sure you have all the tools you'll need for the process by you before
you get started. A really good way to mess up your workshop floor is to start the bleeding
and realize you left your catch can on the other side of the room. So you'll need to make
sure that you have the new brake fluid, a simple plastic piece of tubing, the right size
wrench for your bleeder screw, a screwdriver, a catch can and a lot of towels (just in
case). Always use a new bottle of brake fluid. While you think you just opened this last
bottle, if it's more than a month old, the fluid inside the bottle will have already "expired"
as brake fluid is highly hydroscopic and will absorb moisture out of the air extremely
quickly. This moisture will easily damage your brake systems and force you to do
unnecessary maintenance. While buying a new
bottle may make you spend a few extra
bucks, it'll save you a lot more down the road when you don't wreck your brake system.
You'll also want to make sure that you buy the correct rating of brake fluid. Brake fluid
comes in varying DOT standards from 3 to 5.1 which denotes at what point the fluid boils
at. It's important to stick with the brake fluid that is recommended in your service
manual.
Once you've gathered everything you need, start by covering all the precious parts of
your bike with towels. Brake fluid is pretty caustic and will eat through anything it
touches. If you care about your skin or your paint, try not to let any spill on you or your
bike and maybe even invest in some of our
BikeBandit Nitrile Worx Performance Gloves. From this point on, the process of bleeding your brakes can
vary depending on the type of bike you're working on. Different models will have
different types of brake systems and you should probably check with your service manual
if you are at all unsure about how to go about the process.
If everything important is covered up, attach the end of the brake bleeder to the brake
fluid nipple on your caliper. The brake bleeder should have an arrow pointing to the end
of the tube that should be attached to the caliper. If the tube that you bought for this
doesn't come with a catch, attach some kind of catch can to the other side of the brake
bleeder. This can be any sort of can or bottle that you had intended to just throw away.
It's always a good idea to make sure that the catch can is fairly well secured to the end of
the brake bleeder since you really don't want it to spill any brake fluid. An easy way to
do this is with tape.
Now that you can feel confident that the old brake fluid will make its way out of the cable
without getting everywhere, head up to the handlebar of your bike. You should be able to
easily find the fluid reservoir on the brake throttle side. Remove the screws holding the
cover and diaphragm in place on top of the reservoir and remove them. Try to keep the
diaphragm attached to the cover and set them aside. With the cover off, you'll be able to
see the fluid inside the reservoir.
At this point, if you are doing this whole process without the help of a brake bleeder, or any
other tool that has a valve that will help you keep any air from sneaking up into your
caliper, you might need to borrow the help of a friend or get arm extensions. In order to
allow the brake fluid out while also keeping air out, you'll need to open and close the
bleeder screw as you pump the brake lever. And since your brake lever and bleeder screw
aren't exactly next to each other, you'll probably find it difficult and arm extensions are
both really impractical and probably expensive, to do this job on your own. If you don't
have any friends, you�ll probably need to just grab one of these
Motion Pro Hydraulic Brake Bleeders.
Place your friend down by the caliper with the wrench attached to the bleeder screw in
their trusty hands. You will then pump the brake in order to build up pressure in the brake
system which will push the fluid out. As you pull the brake lever in, have your friend
crack open the bleeder screw and let the fluid flow. Once a bit of the fluid has made its
way into your catch can via the tube, have your buddy close the bleeder screw BEFORE
you release the lever. If you release the lever while the screw is still open, it will suck air
into your brake system. Repeat this process a handful of times while keeping an eye on
the amount of fluid in your reservoir. You never want to let your reservoir run empty as
this will only let in air. Top the reservoir off with fresh fluid as it gets low. The longer
you do this, the clearer the fluid that is coming out of your bike should look. Keep an eye
out for any bubbles in the fluid as it's pushed through the tube as well. You'll want to tap
the brake line a few times as it runs from the reservoir to the caliper to help free any air in
the line. Air can cause you to lose pressure and end up in brake failure. It's always
important to make sure that the fluid in your line has no air left in it.
Once the fluid is clear and free of bubbles, close up the bleeder screw for good and
remove the drain tube from the caliper. If we haven't impressed upon you the dangers of
spilt brake fluid enough already, let us remind you to do this carefully as there will be
fluid remnants in the tube that you'll want to let run into the catch can and not on your
floor.
Some bikes will only have one caliper on the front wheel while larger bikes will have one
on either side of the wheel. If your bike only has the one then you can top off the fluid in
the reservoir one last time and replace the cleaned diaphragm and cover. Then you are
good to go. If your bike has two calipers, you'll need to bleed both individually in order
to flush the old fluid out of the brake line and pistons of each. Just repeat the same
process on the other caliper until the fluid flowing out of it is clear and bubble free as
well. Since a good portion of the brake system was bled when you did the first caliper,
the second should take less time.
Once the calipers have been bled, you'll want to make sure the reservoir is topped off
with fluid and then put the diaphragm and cover back in place. Be sure not to over fill the
reservoir with fluid as this will put too much pressure on your brake system as the fluid heats up.
Pump the brakes a few times to return brake pressure before you start riding.
The Rear
Paying attention to your rear is just as important as paying attention to your front. And,
because they're behind you, the rear brake can easily be forgotten. Out of sight; out of
mind. But that lonely brake needs tender loving care just as much as the front brakes. If
your rear brake is run off of a hydraulic system, you'll need to bleed it when you bleed
the front brake. While the process of this will be pretty much the same as with front
brakes, you'll be bleeding out a different reservoir and master cylinder. You'll need to
locate this part in order to get started. Different models of bikes will have their master
cylinders in different locations. Most will have them located on the right side, by the foot
peg while others will need to have the seat of the bike removed to get to. Some newer
motorcycles have begun to be operated off a system where the front and the rear brakes
will be linked and operated off of the same master cylinder and a pedal. We recommend
checking your service manual for how to bleed these brakes as the process will be quite
different. Once you've found the master cylinder, just do what you do best just like you
did with the front brakes.
Other Options
Of course, we don't always have friends around to help us out with our moto
maintenance and some of us prefer to do our jobs solo. So technology has helped parts
manufacturers to come out with a few handy hand tools that can make bleeding your
brakes a one man job and a whole lot easier.
The Brake Bleeder Tool
Instead of using just a plain rubber tube for the project, grab one of these
BikeMaster Brake Bleeder Tools,
and attach it to the caliper.
These little guys have a check valve in the middle of the tube that lets the brake fluid out
without letting air in so you don't have to open and close the bleeder screw as you pump
the brake lever. So just put one of them on and pump away till your brake fluid comes out
nice and clear.
The Speed Bleeder
Another awesome tool that will cheaply help you bleed your brakes without needing a
friend is a speed bleeder like this
Goodridge Brake Speed Bleeder. These tiny little tools replace the bleeder screw on the caliper and
stay on your bike 24/7. You'll never notice a difference until you go to do the painful task
of bleeding your brakes. These guys also have a check valve inside of them that lets the
fluid out without letting air in which eliminates the need for a second body to open and
close the bleeder screw. Instead, just attach a simple rubber tube with the catch can, open
the speed bleeder like you would the bleed screw and pump that brake lever. When your
fluid has been completely replace, just close up the speed bleeder, remove the tube, top off the reservoir,
replace the reservoir cover and be on your merry way after pumping the brakes a few times to return pressure.
Sizes will vary depending on the bike so check the
size of your bleeder screw and buy the speed bleeder accordingly.
When installing a speed bleeder to your bike, it's always better to do it on a brake system
that is already full of fluid. Many people think that the best time to install them is right
after you've put new bake lines on. Putting them on an empty system, however, will only
make filling your bike with fluid a lot harder. Instead, put speed bleeders on when your
brake system has fluid in it. When installing them, a small amount (hopefully it's small)
of the brake fluid will leak out because you will be switching the screw out while there is
fluid in the system, Remember to keep the reservoir cover on throughout this process.
Keeping it on will keep the system mostly sealed and will keep the brake fluid from just
pouring out once you remove the bleed screw. Be sure to be extra careful not to get this
on anything and put a towel behind the bleed screw before you start to take it off to catch
the brake fluid. Quickly remove the bleed screw and replace it with the speed bleeder.
Use a torque wrench to screw in the speed bleeder to the correct torque in order to avoid
it from being too loose and leaking or to keep it from breaking off in your caliper which
will be costly to repair. And presto! You can leave the speed bleeder on your bike and
easily maintain your brake fluid at any time.
The Vacuum Kit
The third type of tool that will make bleeding your brakes a piece of pie is a vacuum
bleeder kit like this
BikeMaster Vacuum Kit. Kits like this will come with a rubber tube that will attach to a catch can and
then to a vacuum chamber and a hand powered pump. The tube will attach to the bleeder
nipple as always and then you will use the pump to build pressure that will suck the brake
fluid out of the system and down the hose. Once you open the bleeder screw, you'll
notice that the fluid will begin to come out of the caliper without having to hold down the
brake lever. You will have to still make a trip up to your handlebars every few moments
to check the lever of fluid in the reservoir because you still don't want it to run dry. After
the fluid has be let out for a few moments, close the bleeder screw, remove the tube and
do the same thing to the caliper on the other side (if your bike has two calipers on the
front wheel). Continue to repeat this process until you see that the fluid is clear and
contains no bubbles. Then you can top off the brake fluid and replace the reservoir
diaphragm and cover.
Of course, here's another helpful video:
The Air Compressor Method
The method using an air compressor is much like how you use a vacuum kit to bleed your
brakes. The main difference is that, instead of having a hand powered vacuum suck out
the brake fluid, you can attach an air compressor nozzle to the tube and catch can. This is
the fastest way to bleed your brakes though buying an air compressor would be the most
expensive.
With fresh brakes and fresh fluid, you'll know that your brakes will do what you need
them to do and keep you from having to try and find a grassy knoll to crash in to. Just
always be sure to pump those brakes before taking your bike out for a ride in order to
return the pressure in the system. With no pressure, you won't be able to stop, which will
just defeat the whole purpose of changing everything out in the first place.
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