Skip to Content

This site is an affiliate for companies including Amazon Associates and earns a commission on qualifying purchases.

Polaris RZR Brakes Won’t Build Pressure? Here’s Why

Polaris RZR Brakes Won’t Build Pressure? Here’s Why

The Polaris RZR’s brakes usually work like a charm. But if you own one for long enough, you may one day wake up and find that they are struggling to build up pressure. If you’re mystified as to why, look no further.

The top reason why Polaris RZR brakes won’t build up pressure is due to air trapped in the system. This can occur after you change brake components and can be fixed by “bleeding” your brakes. If air isn’t the problem, you may need to replace some of its old parts.

This article will describe how and why air may get trapped in your brake system and then describe how you can fix it. It will also outline other possible reasons your brakes struggle to build pressure.

Air Trapped in Brake Systems

If your brakes aren’t building pressure, odds are you have extra air in them. A telltale sign of air in your brakes is a “softer” or “spongier” feeling as you press down on them. If your brakes are feeling less responsive than usual–or if you happened to change a brake component recently–you probably have air in your brakes.

Here’s how air gets trapped in your brakes–and here’s how you can get it out.

Why Does Air Get Trapped In Your Brake Systems?

There are several ways air can get into your brake system since it runs all throughout your car. Here are the most common reasons.

Recently Changing Brake Components

ATV maintenance is often done by the users themselves instead of by professionals, but the inside of a Polaris RZR isn’t that different from that of a car, and the brake system is just as complex.

Even the most careful amateur is more likely to make a mistake than a professional and accidentally let some air into the system when trying to make a repair. If you recently performed some maintenance on your brakes, you may have let some air in.

Leak in the Brake Line

A cut or leak in the brake line will not only let brake fluid out but also let air in. If there’s a leak in your brakes, you’ll probably hear a hissing sound when you press on your brakes, in addition to the spongy feeling. 

If you need a new brake line, Polaris’ website offers parts for their RZR products on their website (source).

Brake Pads Have Worn Thin

Another possible reason for air getting into your system is shabby brake pads. If your brake pads have been heavily used, they’ve likely become thin. Thin brake pads can cause your brake fluid level to fall quickly, and that will cause air levels to rise in the system. 

If your brake pads have fallen below a thickness of 1 mm (.040 inches), you’ll want to replace them. But you’ll also want to solve the problem of the extra air!

How To Fix Air in Your Brakes

If you think you have air in your brakes, the most important thing you need to note is that you should avoid driving your RZR until the issue is fixed. If your brakes stop working on the road, you can put yourself and your passengers in serious danger.

First, check the fluid level. Look in the front wheel well and find the MIN and MAX marks. If the fluid falls under the MIN mark, there is air in the brake system.

For help with checking on this, Polaris has some tips on brake maintenance on their website (source).

Now that you’ve confirmed there’s an issue with air in the brakes, how do you solve it? Just like on a standard car, you’ll need to go through a process called “bleeding” the brakes.

Bleeding Your Brakes

To bleed your brakes, first, you need to make sure you have everything you need. You’ll need a large car jack to keep your Polaris upright while you work on your brakes. Make sure you have the right kind of screwdriver, as well as the right kind of brake fluid.

If you need to find the right fluid, this Polaris DOT 4 Brake Fluid (link to Amazon) will work for most Polaris models.

Once you’ve collected your materials, here’s what you need to do to bleed the brakes.

  1. Find the bleeder screw and loosen it.
  2. Have a friend or family member pump the brakes. This applies pressure to the system and will force all the air out.
  3. While the brakes are still pumped, tighten the bleeder screw again.
  4. Now have your friend take their foot off the brake. The air should all be gone.
  5. Repeat this process as necessary.

If you need more visual aid, this video will show you how to bleed your Polaris brakes:

Fixing Up A 2015 Polaris RZR 900 - Replacing A Brake Hose And Bleeding The Brakes

Other Possible Reasons for Lack of Pressure in Brakes

If your brake fluid is at the right amount, or you tried to fix it and found that your brakes were still spongy, here are a few other reasons you may be having trouble with your brake pressure:

  • The bolts and screws on a brake system need to be tightened.
  • There’s a kink or knot in the brake line.
  • The brake fluid is old and dirty and needs to be replaced.
  • Seals between the piston and master cylinder are damaged or dry.

All of these problems are easy to fix. In fact, with regular maintenance, you’re more likely to spot these problems and fix them before they cause damage to your brakes. As a rule of thumb, you should perform maintenance on your RZR every six months, even if you don’t have any obvious issues.

So don’t let the possibility of letting air into your brakes prevent you from taking care of your car! Your Polaris RZR will last longer.

Having problems with the pedals in your Polaris RZR? Check out my complete Polaris RZR pedal problems guide to learn more about the problems and how to fix them.

Final Thoughts

If you’re finding that your Polaris RZR’s brakes aren’t building pressure, odds are there’s air in your brakes. Simply fix the air pressure by bleeding the brakes. If that doesn’t work, you likely need to replace or upgrade some of the brake components.

eManualOnline provides descriptive, affordable, and convenient service and repair manuals for cars, trucks, motorcycles, and more. Download one today.