fluid can damage these brake compo
nents leading to brake system failure.
CAUTION
Never reuse brake fluid (like the fluid
expelled during brake bleeding).
Contaminated brake fluid can cause
brake failure.
5. Always keep the master cylinder reservoir cover
installed to keep dust or moisture out of the system.
6. Use only DOT 4 brake fluid or isopropyl alcohol
to wash parts. Never use petroleum-based solvents
on the brake system’s internal components. The
seals will swell and distort, and have to be replaced.
7. Whenever any brake banjo bolt or brake line nut
is loosened, the system is opened and must be bled
to remove air. If the brakes feel spongy, this usually
means air has entered the system. For safe opera-
tion, refer to
Brake Bleeding
in this chapter.
WARNING
When working on the brake system,
do
not
inhale brake dust. It may con
tain asbestos, which can cause lung
injury and cancer. Wear a face mask
that meets OSHA requirements for
trapping asbestos particles, and wash
your hands and forearms thoroughly
after completing the work.
WARNING
Never
use compressed air to clean
any part of the brake system. This re
leases harmful brake pad dust. Use an
aerosol brake parts cleaner (
Figure
1
) to clean parts when servicing any
component still installed on the mo
torcycle.
PREVENTING
BRAKE FLUID DAMAGE
Brake fluid will damage most surfaces on a mo-
torcycle. To prevent brake fluid damage, note the
following:
1. Protect the motorcycle before beginning any ser-
vice requiring draining, bleeding or handling of
brake fluid. Anticipate which parts are likely to leak
brake fluid, and use a large tarp or piece of plastic to
cover the areas beneath those parts. Even a few
drops of brake fluid can extensively damage
painted, plated or plastic surfaces.
2. Keep a bucket of soap and water close to the mo-
torcycle while working on the brake system. If
brake fluid spills on any surface, immediately wash
the area with soap and water, then rinse it thor-
oughly.
3. To help control the flow of brake fluid when re-
filling the reservoirs, punch a small hole into the
seal of a new container. Place this hole next to the
edge of the pour spout.
BRAKE BLEEDING
Bleeding the brakes removes air from the brake
system. Air in the brakes increases brake lever or
brake pedal travel, and it makes the brakes feel soft
or spongy. Under extreme circumstances, it can
cause complete loss of brake pressure.
The brakes can be bled manually or with the use
of a vacuum pump. Both methods are described
here. Only use fresh DOT 4 brake fluid when bleed-
ing the brakes. Do not reuse old brake fluid and do
not use DOT 5 (silicone based) brake fluid.
1. Clean the bleed valve and area around the valve
before beginning. Make sure the opening in the
valve is clear.
2. Use a box-end wrench to open and close the
bleed valve. This prevents damage to the valve, es-
pecially if the valve is rusted in place.
BRAKES
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