2021 YAMAHA YFZ450R brake

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TIPTo check the rear brake fluid level, remove the
seat. (See page 5-10.)
WARNING
EWB02721Improper maintenance can result in loss of
braking ability. Observe these precautions:
Insufficient brake fluid may allow air to enter
the brake system, reducing braking perfor-
mance.
 Clean the filler cap before removing. Use
only DOT 4 brake fluid from a sealed contain-
er.
 Use only the specified brake fluid; otherwise,
the rubber seals may deteriorate, causing
leakage.
 Refill with the same type of brake fluid. Add-
ing a brake fluid other than DOT 4 may result
in a harmful chemical reaction. 
Be careful that water does not enter the
brake fluid reservoir when refilling. Water will
significantly lower the boiling point of the flu-
id and may result in vapor lock.
NOTICEECB01161Brake fluid may damage painted surfaces or
plastic parts. Always clean up spilled fluid im-
mediately. As the brake pads wear, it is normal for the brake
fluid level to gradually go down. A low brake fluid
level may indicate worn brake pads and/or brake
system leakage; therefore, be sure to check the
brake pads for wear and the brake system for
leakage. If the brake fluid level goes down sud-
denly, have a Yamaha dealer check the cause be-
fore further riding.EBU24294Changing the brake fluidHave a Yamaha dealer change the brake fluid at
the intervals specified in the periodic maintenance
chart. In addition, have the oil seals of the master
Specified brake fluid:
DOT 4
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9
cylinders and calipers as well as the brake hoses
replaced at the intervals listed below or whenever
they are damaged or leaking.

Oil seals: Replace every two years.
 Brake hoses: Replace every four years.
EBU24396Checking the front brake lever free
playThere should be no free play at the brake lever
end. If there is free play, have a Yamaha dealer in-
spect the brake system.
EBU24616Checking the brake pedal heightPeriodically check the brake pedal height. If the
brake pedal is not positioned as specified, have a
Yamaha dealer adjust it.
1. No brake lever free play
1
1. Brake pedal heightBrake pedal height: 11.7 mm (0.46 in)
1
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9
EBU24717Adjusting the parking brake free playPeriodically check the cable length “A” and adjust
if necessary.1. Release the parking brake by moving the parking brake lever to the right.
2. Fully loosen the locknut and the adjusting bolt at the rear brake caliper. 3. Slide the rubber cover back at the brake ca-
ble.
4. Loosen the locknut.
5. Turn the parking brake free play adjusting nut in direction (a) to increase the cable length,
and in direction (b) to decrease it.
TIPIf the cable length cannot be adjusted to specifi-
cation, consult a Yamaha dealer. 6. Tighten the locknut on the brake cable.
7. Slide the rubber cover to its original position.
1. Adjusting bolt
2. Cable length “A”
3. LocknutCable length “A”:47–51 mm (1.85–2.01 in)
1
2
3
1. Locknut
2. Parking brake free play adjusting nut
3. Rubber cover
1
2
3
(b)
(a)
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9
8. Turn in the adjusting bolt at the rear brake cal-
iper until it feels tight, then turn it out 1/8 turn
and tighten its locknut to the specified torque.
NOTICE: When tightening the locknut,
hold the adjusting bolt with a wrench so
that it does not turn together with the lock-
nut.
[ECB00522]
WARNING
EWB02091Operating with improperly serviced or adjust-
ed brakes could cause the brakes to malfunc-
tion, resulting in reduced braking
performance. This could increase the chance
of a collision or accident. After adjusting the
parking brake free play, block the rear of the
ATV off the ground and spin the rear wheels.
Check to make sure there is no brake drag. If
brake drag is noticed, perform the adjustment
again.
EBU24744Brake light switchesThe brake light, which is activated by the brake
pedal and brake lever, should come on just before
braking takes effect.
The brake light switch for the brake pedal can be
adjusted as follows, but the front brake light
switch should be adjusted by a Yamaha dealer.
Turn the rear brake light switch adjusting nut while
holding the brake light switch in place. To make
the brake light come on earlier, turn the adjusting
nut in direction (a). To make the brake light come
on later, turn the adjusting nut in direction (b).
Tightening torque:
Locknut (rear brake caliper):16 N·m (1.6 kgf·m, 12 lb·ft)1. Rear brake light switch
2. Rear brake light switch adjusting nut
1
2(a) (b)
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WARNING
EWB02582Inspect cables frequently and replace if
damaged. Corrosion can result when the ca-
ble sheaths become damaged, and cables
can also become frayed or kinked, which
could restrict the operation of controls and
lead to an accident or injury.
 Always make sure all control cables work
smoothly before you begin riding in cold
weather. If the control cables are frozen or
do not work smoothly, you could be unable
to control the ATV, which could lead to an
accident or collision. EBU24923Checking and lubricating the brake
and clutch leversThe operation of the brake and clutch levers
should be checked before each ride, and the lever
pivots should be lubricated if necessary. Brake lever
Recommended lubricants:
Brake lever:Silicone grease
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Clutch lever
EBUM0171Checking the shift pedalThe operation of the shift pedal should be
checked before each ride. If operation is not
smooth, have a Yamaha dealer check the vehicle.EBU28872Checking and lubricating the brake
pedalThe operation of the brake pedal should be
checked before each ride, and the pedal pivot
should be lubricated if necessary.
EBU38880Checking the wheel hub bearingsThe front wheel hub bearings must be checked at
the intervals specified in the periodic maintenance
chart. If there is play in a wheel hub or if a wheel
does not turn smoothly, have a Yamaha dealer
check the wheel hub bearings.Recommended lubricant:
Lithium-soap-based grease
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98. Adjust the headlight beam if necessary.
EBU25562Adjusting a headlight beamNOTICEECB00691It is advisable to have a Yamaha dealer make
this adjustment. To raise a headlight beam, turn the headlight
beam adjusting bolt in direction (a).
To lower a headlight beam, turn the adjusting bolt
in direction (b).
EBU26922Brake/tail lightThis model is equipped with an LED type of
brake/tail light.
If the brake/tail light does not come on, have a
Yamaha dealer check it.EBU25653Removing a wheel1. Park the ATV on a level surface.
2. Loosen the wheel nuts.
3. Elevate the ATV and place a suitable stand under the frame.
4. Remove the nuts from the wheel.
5. Remove the wheel.
1. Headlight beam adjusting bolt
1
(a)
(b)
1. Wheel nut
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EBU25861
CLEANING AND STORAGE
EBU25903CleaningFrequent, thorough cleaning of your ATV will not
only enhance its appearance but will improve its
general performance and extend the useful life of
many components.1. Before cleaning the ATV: a. Block off the end of the exhaust pipe toprevent water entry. A plastic bag and
strong rubber band may be used.
b. Make sure the spark plug and all filler caps are properly installed.
2. If the engine case is excessively greasy, apply degreaser with a paint brush. Do not apply
degreaser to the chain, sprockets or wheel
axles.
3. Rinse the dirt and degreaser off with a garden hose. Use only enough pressure to do the
job. WARNING! Wet brakes may have re-
duced stopping ability, increasing the
chance of an accident. Test the brakes af-
ter washing. Apply the brakes several
times at slow speeds to let friction dry out
the linings.
[EWB02312]
NOTICE: Excessive wa- ter pressure may cause water seepage
and deterioration of wheel bearings,
brakes, transmission seals and electrical
devices. Many expensive repair bills have
resulted from improper high-pressure de-
tergent applications such as those avail-
able in coin-operated car washers.
[ECB00712]
4. Once most of the dirt has been hosed off,
wash all surfaces with warm water and mild,
detergent-type soap. An old toothbrush or
bottle brush is handy for hard-to-reach plac-
es.
5. Rinse the ATV off immediately with clean wa- ter and dry all surfaces with a chamois, clean
towel or soft absorbing cloth.
6. Dry the chain and lubricate it to prevent it from rusting.
7. Clean the seat with a vinyl upholstery cleaner to keep the cover pliable and glossy.
8. Automotive type wax may be applied to all painted and chrome plated surfaces. Avoid
combination cleaner-waxes. Many contain
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