Editor’s Note: This article on changing brake pads and bleeding the brakes on a snowmobile first appeared in the Service & Repair department of the January 2024 issue of Snow Goer magazine. For more snowmobile-dedicated content, subscribe today.

You don’t have to be the sharpest tool on the tree or the brightest bulb in the drawer to figure out that the brake is a rather important part of your snowmobile. It would likely be a rather short yet eventful ride if your brake fails!

The hydraulic disc brakes found on modern snowmobiles are quite effective in providing an immediate reaction to a rider input, and they are rather simple in their operation.

A mechanical squeeze on the brake lever is converted into hydraulic force in the handlebar-mounted master cylinder. That force is then transferred via the brake fluid through the brake lines to the brake caliper. The caliper’s piston(s) then squeezes brake pads against the rotating brake rotor, generating enough friction to slow the vehicle. It all happens in an instant.

The most obvious wear items in the system are the brake pads. A set of brake pads typically lasts several thousand miles, but their rate of wear will vary greatly depending on the rider’s habits and conditions in which they ride.

Wherever you are upon the brake-use continuum, you should peek at the thickness of your brake pads about every 500 miles to see their level of wear. A set of brake pads typically only costs $40-$100 and installing them is a rather easy process that usually doesn’t require any specialty tools or bleeding of the brake lines.

That said, we’ll also provide an overview of the brake-bleeding process for those who need that service as well.

Replacing The Pads

While it varies by make and model, it’s generally rather easy to get a top-down view of the brake pads within the brake caliper.

Some brake pads have a groove cut in the center so you can see their level of wear. If that groove is starting to disappear within the rest of the pad, it’s time to replace them. Other brake pads have no such groove, which means the owner must know or have a sense of the pad’s original thickness to be able to recognize when they are down to their last 25 to 30 percent.

The inspection is key. Don’t wait for an audible cue to tell you that it’s time to replace the pads. If you’re hearing a grinding metal-on-metal noise, it may already be too late and you’ll end up with the more expensive and labor-intensive task of replacing the brake rotor as well.

To illustrate this story, we borrowed a friend’s 2013 Polaris 600 Rush Pro-R and slapped new brake pads on it. Ordering new, original-equipment brake pads from a Polaris dealership would have cost $99.99, but the arguably just-as-good DP-branded high-friction sintered metal brake pads we installed sold for $43.15 on Denniskirk.com.

Replacing the pads on this model couldn’t have been much easier. First, we needed to remove the right-side body panel to get access to the brake caliper, which is mounted on the jackshaft on modern Polaris sleds. We also removed the snowmobile’s hood (photo 1) to get brake ducting out of the way and provide more room to take pictures.

The front and rear pads on each side of the brake rotor typically but don’t always wear at the same rate, so make sure to check both in your periodic inspections, and replace both when that time arrives.

In our case, the brake pad material was mounted on a metal host plate shaped like a griddle with a “handle” facing straight up. A mounting pin (photo 2) went through a bracket on the caliper and then through a hole atop each pad’s host plate.

To prevent the new pads from dropping down into the belly pan, hold the top of the far-side host plate with your fingertips (photo 3) or a needlenose pliers and slowly start pull out the mounting pin. Once the pin is past that first brake pad, that pad can be pulled out of the caliper. Then grab the tip of the second host plate while pulling the pin the rest of the way out of the caliper.

Now’s a good time for a second inspection. Eyeball the pads for signs of uneven wear, and also check the rotor to make sure it’s flat and without worn grooves. If there are grooves or if the rotor is warped (which you may have sensed if you felt pulsation at the brake level), it’ll need to be replaced.

If everything looks good, you’re already set for reassembly.

If you’re lucky (which we were), the pistons that normally push the pads toward the rotor stayed retracted, which will allow the new pads to drop right into place. However, if the pistons partially filled the gap where the pads previously sat, you’ll need to physically push them back into the calipers. It is best to do this step with an angled pry bar (photo 4) or even a C-clamp if there’s room. But use something broad that can push the piston back into the caliper evenly instead of pushing it back in at an angle. Ideally, you’ll be able to get enough leverage to make the piston(s) retract without removing the master cylinder cover.

Once you have clearance, grab the tip of the near-side brake pad’s host plate with your fingertips or pliers, with the pad material facing the rotor, lower it into place and run the pin through it (photo 5). Then repeat with the second brake pad and secure the mounting pin. We’d suggest raising the track off the ground with a track stand and testing the brake’s actuation several times before riding.

Some Caveats

As stated, our pad swap was rather easy, but there may be variations based on the make and model of your sled. For instance, many modern snowmobiles now have the brake rotor and caliper mounted at the end of the driveshaft instead of the jackshaft.

To service those brakes, the brake rotor cover on the side of the tunnel near the footwell needs to be removed to inspect the pads and change them if needed. But other than removing the panel, the process is much the same.

In other instances, the caliper will need to pulled off the rotor to replace the pads. Often that just involves removing two additional bolts.

Bleeding The Brakes/Changing The Fluid

While changing pads, it may be a great time to give your brake system an “oil change” of sorts.

Brake fluid gets dirty over time. It can also partially break-down if it gets overheated with aggressive use and can get contaminated by dirt or moisture. Getting air in the system is also a problem. If your brakes are rather squishy feeling at the brake lever, take the time to bleed them. But in general, changing brake fluid every season or two should be a part of a regular maintenance schedule.

Items you’ll need include:

• An approximately foot-long piece of clear hose – we used quarter-inch fuel line, but it can vary;

• An empty bottle to catch the old brake fluid;

• A container of new brake fluid that matches your sled’s brake system (usually labeled Dot 4, though some systems use Dot 3 or Dot 5. Dot 3 and Dot 4 brake fluids can be mixed, but never mix either with silicone-based Dot 5);

• Shop rags or towels;

• Common hand tools to turn the bleed screw and remove the master cylinder cover.

Start by preparing to capture any spilled brake fluid. It is highly corrosive and can damage plastic or metal surfaces it contacts, so you’ll want to keep it off other brake components as well as body panels and such.

Place one end of the clear hose on the nipple-shaped bleed screw coming out of the brake caliper, with the other end of the hose leading to your catch container (photo 6). A clear water or soda bottle works well for this. Set that bottle/container someplace stable – on the running board, floor, belly pan, etc. – and preferably lower than the caliper with no loops in the clear hose so gravity can be your friend.

Next, turn your attention to the handlebar-mounted master cylinder. Before removing its cover, you’ll want to get the master cylinder as level as possible. That may require adjusting its position on the handlebar or turning the handlebar itself in one direction or the other.

Lay a towel or rag beneath the master cylinder and handlebar to protect surfaces from spills, then carefully remove the master cylinder cover (photo 7). It’s often held in place by two small screws or bolts and has a gasket underneath. If the fluid is low, add some to make sure you don’t introduce air into the system with the following steps.

Brake bleeding is best done as a two-person team. The person working at the caliper should loosen the bleed screw (usually it’s just a quarter turn with an 8mm, ¼-inch, or 5/16-inch wrench) and then instruct the person at the handlebar to slowly and steadily squeeze and hold the brake handle (photo 8). Fluid will come out through the bleed screw, into the hose you attached and will be captured in the bottle. When the fluid stops running, the bleed screw should be closed and then the brake handle can be released.

The person operating the brake lever has a second duty: Adding new fluid into the master cylinder during the process to prevent air from getting into the system.

That series of steps – open the bleed screw, squeeze and hold the brake lever, close the bleed screw and release the brake lever – is repeated appoximately 10 times until it’s evident that clear/clean brake fluid is coming out the clear hose.Then tighten the bleed screw, top off the master cylinder to the appropriate level, install the cover and squeeze the brake lever several times to ensure it has good pressure at the handle.

If the feel at the brake handle is squishy after pumping the brakes a couple of times, you still have air in the line and you’ll need to renew the bleeding process. 

As always, test the function of the snowmobile brake with the rear of the sled on a jack stand before riding.