By: Tim Donaldson

"How-To" - Changing Hydraulic Disk Brakes

Mud buildup that accelerates pad wear.

Isaac Newton, the father of the Laws of Motion, stated that an object in motion tends to stay in motion until an equal and opposite force is acted upon it. Without adequate brakes on an ATV to act as an opposing force to forward momentum, a rider may have to rely on other naturally available objects, such as trees or large rocks, to act as the necessary stopping force! In order to prevent a potential disaster, it is important to maintain a healthy braking system.

There are many different types of braking systems on ATV's, even varying in style from front to rear wheel. To name a few, the range includes: triple-sealed hydraulic drum brakes, drum and shoe brakes, wet brakes, and the basic hydraulic disk brake system.

New Vs. Old Pads

Of the styles of systems, the task of changing disk brakes is the least arduous and time consuming. However, due to their direct exposure to the elements (mud and water), you may find that changing brake pads 3 times in one riding season is not uncommon for those riding in similar types of harsh environments, especially without adequate cleaning afterwards.

With such a limited duty-cycle, riders may find it beneficial to acquire the basic skills necessary to change their own brake pads, rather than paying expensive service fees.

This "How-To" will address changing the front hydraulic disk brakes on a 2006 Kawasaki Prairie 360 4 x 4. Although the specific details may vary from make and model, the fundamental techniques are basically the same. Also, consider that I am an enthusiast trying to save a few bucks, not a professional mechanic.

Caliper and Piston

Steps

1.  Loosen wheel lugs and remove wheel. Before lifting the ATV off the ground, loosen the wheel lugs. It is easier to apply the necessary force to break the lugs free, when the wheels are unable to spin. Avoid applying a lot of brake pressure. Applying the brakes will extend the caliper piston (squeezing pads on disk), making it more difficult to remove the pads later. For added safety, slide one of the wheels under the ATV-in case of jack or stand failure.
    
2.  Clean dirt and debris from the caliper, brake pad, and disk area. This is the root cause of the excessive brake wear. CV boot guards and A-arm skid plates are great for machine protection but create nice hiding spots for dirt and debris that makes them difficult to clean.
    
3.  Loosen brake pad fasteners. Do not remove bolts. Simply loosen them. Locking tabs surrounding the bolt heads can be pushed back with a screwdriver.
    
4.  

   Locking tabs must be pushed back away from bolt head to allow free turning.

   Remove brake calipers (the device which clamps pads via hydraulic piston) from the disk. The calipers are mounted onto the wheel knuckle by two bolts. Kawasaki engineers cleverly molded an access hole in the knuckle which accommodates a ratchet with extension, making the job much easier.
    
5.  Remove old pads from brake caliper. Since previously loosing the fastening bolts, no awkward leverage will be necessary to slacken bolt grip.
    
6.  Place new pads into caliper and replace the mounting bolts. As mentioned earlier, excess braking during preliminary prep will extend the cylinder piston. In order to successfully replace the pads so that there is sufficient clearance about the disk, it may be necessary to manually or forcefully retract the cylinder. Remember that the new pads are much thicker than the old ones that you just removed. A small wood block with a c-clamp will return the piston to its "home" position, allowing the new pads to easily slide over the disk into position.
    
7.  Remount the brake caliper.
    
8.  

   New pads in caliper viewed with fastening bolts.

   Tighten pad fasteners and restore locking tabs.
    
9.  Remount wheels and tighten lugs.
    
10.  Carefully test brakes before flying out of the garage or down the trail. Hopefully, this one is common sense!

Part of purchasing a quad is upkeep and maintenance. If you are considering a new purchase, take into account the types of riding environments that will typically be encountered; and your comfort or willingness to perform related maintenance tasks, as a result. Many ATV manufacturers have considered the harsh environments and abuses that riders encounter. Evaluate the pros and cons that each has to offer. Have fun, and don't run into any trees or rocks out there! Make sure you have a set of great working brakes!