What to Do When Your Snowmobile Brakes Lock Up


It’s any snowmobiler’s worst nightmare: you want to come to a stop, but your sled just isn’t cooperating. Without control of your brakes, you’re at risk of crashing into anyone or anything that comes into your path. What do you do in such an emergency?

If your snowmobile brakes suddenly lock up, stay calm and begin trying to get your snowmobile to stop. If the brakes are burning, riding through thicker snow could cool them down before they alight, but you still want to get off your sled immediately. Afterward, flush the brake fluid. 

In this article, we’ll discuss your sled’s braking system, the issues that can cause the brakes to lock, and what to do if it happens. We’ll even suggest some pointers for getting your sled to a mechanic when it’s having brake issues. Keep reading! 

Snowmobile Brakes 101: What You Need to Know 

Before we get into brake failure, it’s best if you’re well-acquainted with your snowmobile’s braking system. 

Snowmobiles rely on hydraulics to power the brakes. Within the braking system is a rotor, a clapper, and brake pads. When you put your foot on your sled’s brake, the hydraulics activate the clapper, which applies pressure via the brake pads to the rotor. This all happens courtesy of the brake lever.

The brakes themselves may last the life of your snowmobile, but the components within the braking system more than likely will not. If these components begin to wear down, it’s not a good idea to ignore their current state. Like you wouldn’t want to get behind the wheel of a car or truck with possible faulty brakes, the same should be true of your snowmobile.

Besides the parts of the brake system (especially the brake pads) wearing down, your sled’s brake system also needs brake fluid refills every now and again. Most brake fluid is comprised of glycol, which absorbs water due to its hygroscopic properties. Glycol brake fluid is also low-moisture, as its boiling point is higher than average so your brake fluid lasts longer. 

Never use silicon brake fluid for your snowmobile, even if you would for other vehicles. It lacks the moisture absorbency you need. You can typically tell silicon and glycol brake fluid apart because the former will be purple. 

What Causes Snowmobile Brakes to Lock Up?

Now that you understand a bit more about the parts that make up your snowmobile’s hydraulic braking system, we can take a closer look into what may have stopped working and led to your brakes locking up.

Parking Brake Is On

Your snowmobile comes equipped with a parking brake, which is meant to maintain your sled’s stopped position when you park. The parking brake is a useful feature of modern snowmobiles, but if yours is set to on when you’re not parked, the parking brake could interrupt your ability to stop your sled.

If it turns out that your parking brake was activated when it wasn’t supposed to be, then all you have to do is set it back into position and voila, your problem is fixed. Yes, it really is that simple in this case. 

Overheating Brakes

More often than not though, your snowmobile brakes locking up won’t have such an easy fix. Another reason the brakes might have failed on you is that they’ve overheated. If your brake pads fall out of position and begin dragging, this is one reason your brakes can begin heating up quickly.

Most of the time, you’ll smell your overheating brakes before you see them. What exactly is that odor you’re sniffing? Probably plastic, as the fuel pipes adjacent to your sled’s brake rotors are often made of plastic. 

If your brakes overheat, you want to find a way to stop your sled and get off it right away. Plastic burns fast, and it’s only a matter of time before your whole snowmobile could go up in flames. It’s not safe to stick around. 

Leftover Brake Fluid

Leaving brake fluid in your snowmobile from one season to another isn’t the best idea. Glycol brake fluid, although it’s absorptive, can reach capacity, leaving it unable to suck up more moisture. 

When the brake fluid hits its saturation point, any moisture that forms thereafter cannot be absorbed. Thus, you end up with a lot of condensation and even water that can damage the braking system, breaking down seals and corroding metal components.

Even more damaging is the brake fluid becomes contaminated, decreasing the previously high boiling point. Now it doesn’t take much hard braking at all for the brake fluid to hit its boiling point, which is dangerous. Your braking lever can even degrade, taking on a sponge-like texture that renders it useless. 

As if all that wasn’t bad enough, mixing new and old brake fluid can degrade the quality of the new stuff, leaving you unable to stop in some instances.

Improper Brake Fluid Type

Also, a poor idea is using silicon brake fluid when you really need glycol braking fluid instead. Silicon fluid lacks any absorption abilities, so you will have the above issues. 

Lack of Fluid Flushing

Another task you have to commit to as a snowmobile owner is flushing your snowmobile brake fluid on a two-year basis at least. With a brake fluid testing device, you can determine whether your snowmobile brake fluid has an adequate boiling point.

You’re aiming for a boiling point of around 400 degrees Fahrenheit for newer fluid. It’s okay if your brake fluid is a bit older and the fluid reaches a temperature of 330 degrees, but no lower than that. 

If it’s time for new brake fluid, then access the master cylinder, taking the cover off. Clean the lid of the cover as well as the cover itself, then the reservoir. Feed a clear tube into the master cylinder’s reservoir and begin to pass brake fluid through the tubing to a container, which you also want to be transparent so you can see the brake fluid colors change. 

You might have some air bubbles with your fluid, but this is normal. Until all the bubbles are gone, keep flushing. 

Brake Fluid Reservoir Clogged

That’s how flushing your brake fluid should go, but if your brake fluid reservoir is gunked up, then fluid can’t flow through, let alone the bubbles. The opening here is about pin-sized, but if it gets blocked, it’s still not good. 

Warped Brake Rotor

If your brake system had previously overheated, your brakes may still be acting up even after that episode. This could be due to your brake rotors, which got literally bent out of shape due to the high heat they were exposed to. You should be able to push the brake rotor back into shape in most instances. Otherwise, replacing the rotor is your next best bet. 

Damaged Master Cylinder

The master cylinder’s seals can also wear away, especially when you leave fluid in the braking system, as we talked about before. If so, then you’ll want to replace the seal immediately so the master cylinder doesn’t send dirt and debris into your braking system. 

Broken Caliper 

Your snowmobile brake system also includes brake calipers, which house the brake pads. Check your calipers at least once every season to assess their condition. Some handy snowmobilers decide to buy a seal kit and then rebuild their damaged calipers themselves. You can do that if it suits you or just order a new one and let your snowmobile mechanic install it. 

What to Do When Your Snowmobile Brakes Lock Up?

Whether it’s accompanied by a burning smell or not, if your snowmobile won’t stop when it’s supposed to, you’re in a very risky predicament. It’s easy to let the fear overtake you in a situation like this, but then you’re not thinking clear-headedly. 

Take a breath and remember to be proactive, and quickly at that. First, reach for your parking brake. If it’s not the parking brake that won’t let you stop, then try to guide your sled to a snowier area so the snow might cool down the overheating braking system and engine.

When you’ve gotten your snowmobile to a stop, turn it off and wait until it cools down. Then you can take a closer look at the braking system to determine what may have gone wrong. Start with the areas we just discussed.

If you suspect that your master cylinder is clogged, then you need to open the brake fluid reservoir as you did when you flushed your braking fluid. Check for a return port, often a tiny one. This port sends pressure to the brake reservoir, and you’ll need something pin-shaped to unplug it. No, a pen won’t work here as it’s too big.

Can You Drive Your Snowmobile on Locked Brakes? How? 

Your brakes still aren’t really working, so you need to see your mechanic right away. The problem is, your snowmobile is stranded in the middle of the trail. You’re afraid if you start up the sled again that it won’t be able to stop, but you can’t stay here either. What do you do in such a situation?

Well, you can remove the brake pads in the caliper. To do this, you need to take out the tiny pin that keeps the brake pads in place. Doing this will also let you know whether you have a jammed brake pad issue, which too can prevent your brakes from working. 

You can ride your snowmobile back to your vehicle (or even all the way home) from here, even without brake pads. You want to take things incredibly slow, as your brakes certainly won’t work reliably with the brake pads out. Once you reach your destination, stop using your snowmobile until you can get it addressed by a mechanic. Also, make sure to put your brake pads back on at some point. 

Final Thoughts

Your snowmobile’s hydraulic braking system can lock up for a variety of reasons, leaving you unable to stop at a moment’s notice. Although your brakes failing can be a horrifying ordeal, keeping your head on straight and remaining cool and collected is key. This way, you can figure out what’s causing the brake lock, try to fix it, or get your sled to a pro. Best of luck! 

Geoff Southworth

I am a California native and I enjoy all the outdoors has to offer. My latest adventures have been taking the family camping, hiking and surfing.

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