BRAKING TIPS: We know, you have enough things to worry about. Work, politics, kids, girlfriends, wives and combinations thereof take up about 90 percent of your brainpower. They should. We just ask that you take a little time to think about brakes.
(1/13/2011)
PRO MECHANIC BRAKING TIPS
Speeds that go up must eventually come down—sometimes in a hurry
Modern quads have three different types of brakes. Big machines like
the Kawasaki Brute Force 750 have sealed, multidisc brakes that operate
much like a wet clutch. For the most part, these are indestructible,
even if they are heavy, expensive and complicated. At the other end of
the ATV universe we have drum brakes. These are simple and inexpensive,
and are only used on lightweight, entry-level machines. The vast
majority of modern ATVs have hydraulic disc brakes, which offer
excellent power, light weight and good reliability. But they aren’t
indestructible. We talked to a number of brake experts, including Aaron
Hodak of Galfer Brakes, to get these basic brake tips.
1. KNOW YOUR BRAKES
Back in the days of Blasters and Banshees, you had nothing between you
and that big tree but your brakes. But in the era of four-strokes,
things have changed. Your motor shares the burden of stopping, so
despite having heavier machines, brakes can last longer. Even if you
have a CV transmission, most offer some sort of simulated engine
braking. Small quads with centrifugal clutches have an interesting
trait. They have engine braking down to very low rpm, then suddenly
freewheel. This isn’t a factor unless you are idling and then start
rolling downhill. You have to gas it briefly to engage the motor before
compression can slow you down. The point of all this is to know your
quad so that you can make your brakes last longer.
2. FRESHEN YOUR FLUID
Heat is the enemy. Brake fluid is made to withstand incredible
temperature, but eventually, you’ll over do it. That’s when you need to
replace your old fluid with new stuff. Brake fluid absorbs moisture from
the atmosphere, and it can break down with repeated cycles of hot and
cold. Change your fluid using DOT 4 fluid from a bottle that’s freshly
opened. A previously opened bottle will be contaminated with moisture
after about six months and will be no better than the stuff in your
master cylinder. That’s bad because water acts very different from brake
fluid when it’s heated. That’s why we don’t use water in our brakes.
3. DON’T WAIT TOO LONG
If you still have a few millimeters of brake pad material before you go
metal to metal, don’t get cocky. In many cases, modern brake systems
don’t have enough fluid capacity to push the pistons out more than 5mm
or so. If you have 8mm of brake pad material, that last 3mm is just for
looks. The good news is that brakes often stop working before going
metal on metal and ruining your discs.
4. USE THE RIGHT PADS
The more material on the brake pad, the more insulation you have between
the disc and the caliper, so heat fade is less of an issue. Many
companies like Galfer sell different types of compounds. Semi-metallic
are good general-use pads. Sintered pads are generally more aggressive
and can withstand higher heat, but will wear a disc more rapidly. Kevlar
or Organic pads are softer, but will wear out sooner. When you switch
pads, you’ll get the best performance with a new disc. At the very
least, you should clean your disc to remove the old pad material.
5. REFACE YOUR DISC
Worn out discs are often to blame for weak brakes. Does your disc have
little grooves and scores? That reduces your braking surface
dramatically. You can’t take your disc to an automotive machine shop for
resurfacing because you don’t have enough material to lose. But you can
do some resurfacing of your own with a sanding block and 600-grit
sandpaper.
6. THE HOSE IS NOT FOREVER
The most neglected part of your brake system is the hose. Your quad came
with an inexpensive rubber hose that wears out in about a year. When
that happens, much of the force that you apply with your hand or foot is
expanding the line like a balloon. Steel braided lines will give an old
quad a very cost-effective upgrade in performance.
Riders underestimate the braking power that may be lost from old flexi rubber hoses. Steel braided lines can give new life to old binders.
7. BLEED IT RIGHT
It’s hard to beat the old-fashioned pump-crack-and-bleed technique as
long as you keep several things in mind. Start with the wheel that’s
farthest from the master cylinder. Don’t introduce air into the system
at the bleed valve. Remember, the bleed nipple on your caliper uses a
tapered pipe thread. Air can easily go around the threads; it doesn’t
have to go through the front door. Make sure the nipple is fully seated
before you release pressure on the brake or you will suck more air into
the brake, regardless of any hoses or tools you have connected to your
bleed nipple. Gary Jones has his own way of bleeding brakes, as do most good mechanics. Just remember that brakes want to rid themselves of air, and that bubbles travel upwards, so you’ll be fine. The bleed nipple on most brake calipers uses a pipe thread. This means the fitting is tapered and that air may go around the threads, no matter how well the hose is fastened in place.
8. STOP THE NOISE
Are your brakes squealing? More often than not, this is because you have
contamination on your rotor. You might have a little organic pad
material that doesn’t like your new semi-metallic pads or vice versa.
Clean your disc carefully and wet sand it. You’ll see the old pad
material coming off.
9. CHOOSE THE RIGHT ROTOR
Different kinds of mud require different kinds of rotors. The original
Galfer Wave rotor was designed to clean sticky mud from your pads, and
it does that well. In abrasive mud, many riders like solid rotors with
no holes whatsoever. This doesn’t really help performance, but you can
get longer pad life.
Galfer originated the Wave
rotor in order to help clean the pads of mud and debris. A side benefit
is that this design is lighter.
10. BE AWARE
More often than not, bad brake habits are the cause of brake failure. If
you ride your brakes, take steps to break yourself of the habit. Adjust
your brake lever height lower or use a stiffer return spring. Or, just
think before you stomp.
WARNING: Much of the action depicted in this magazine is potentially dangerous. Virtually all of the riders seen in our photos are experienced experts or professionals. Do not attempt to duplicate any stunts that are beyond your own capabilities. Always wear the appropriate safety gear. Copyright 2008 Hi-Torque Publications, Inc. All rights reserved. Console Login
