brake YAMAHA YFZ450 2008 Owner's Manual

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in water deeper than that specified in your
Owner’s Manual. Remember that wet brakes
may have reduced stopping ability. Test your
brakes after leaving water. If necessary, apply
them several times to let friction dry out the lin-
ings. If the ATV is operated through deep or
fast flowing water, the tires may float, causing
loss of traction and loss of control, which
could lead to an accident.
Test your brakes after leaving the water. Do not
continue to ride your ATV without verifying that youhave regained proper braking ability.CAUTION:
ECB00240
After riding your ATV in water, be sure to drain
the trapped water by removing the check hose
at the bottom of the air filter case. Wash the
ATV in fresh water if it has been operated in
salt water or muddy conditions.

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slide. Applying the brakes or accelerating is not
recommended until you have corrected the slide.
With practice, over a period of time, skill at con-
trolled sliding can be developed. The terrain
should be chosen carefully before attempting such
maneuvers, since both stability and control are re-
duced. Bear in mind that sliding maneuvers should
always be avoided on extremely slippery surfaces
such as ice, since all control may be lost.
WARNING

EWB01661
Learn to safely control skidding or sliding by
practicing at low speeds and on level, smoothterrain.
On extremely slippery surfaces, such as ice,
go slowly and be very cautious in order to re-
duce the chance of skidding or sliding out of
control.
WHAT TO DO IF...
This section is designed to be a reference guide
only. Be sure to read each section on riding tech-
niques completely.
WHAT TO DO...

If your ATV doesn’t turn when you want it to:
Bring the ATV to a stop and practice the turning
maneuvers again. Be sure you are putting your
weight on the footboard to the outside of the
turn. Position your weight over the front wheels
for better control. (See page 7-12.)

If your ATV begins to tip while turning:
Lean more into the turn to regain balance. If nec-
essary, gradually let off the throttle and/or steer
to the outside of the turn. (See page 7-12.)

If your ATV starts to slide sideways:
Steer in the direction of the slide if you have the
room. Applying the brakes or accelerating is not
recommended until you have corrected the

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slide. (See page 7-20.)

If your ATV can’t make it up a hill you are trying
to climb:
Turn the ATV around if you still have forward
speed. If not, stop, dismount on the uphill side of
the ATV and physically turn the ATV around. If
the ATV starts to slip backwards, DO NOT USE
THE REAR BRAKE – the ATV may tip over on
top of you. Dismount the ATV on the uphill side.
(See page 7-14.)

If your ATV is traversing a sloping surface:
Be sure to ride with your weight positioned to-
wards the uphill side of the ATV to maintain
proper balance. If the ATV starts to tip, steer
down the hill (if there are no obstacles in your
way) to regain balance. If you discover that the
ATV is going to tip over, dismount on the uphill
side. (See page 7-14.)

If your ATV encounters shallow water:
Ride slowly and carefully through slow moving
water, watching for obstacles. Be sure to let wa-
ter drain from the ATV and CHECK YOUR
BRAKES FOR PROPER OPERATION when
you come out of the water. Do not continue to
ride your ATV until you have regained adequate
braking ability. (See page 7-18.)

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EBU21864
General maintenance and lubrication chart
NO. ITEMCHECK OR MAINTENANCE
JOBINITIAL EVERY
Whichev-
er comes
firstmonth 1 3 6 6 12
km
(mi)320
(200)1300
(800)2500
(1600)2500
(1600)5000
(3200)
hours 20 80 160 160 3201 Air filter element


Clean and replace if necessary.Every 20–40 hours (more often in wet or
dusty areas)
2
*
Clutch

Check operation and adjust if necessary.
√ √√√
3
*
Front brake


Check operation and correct if necessary.

Check fluid level and ATV for fluid leakage, and
correct if necessary.
√√√√√

Replace brake pads. Whenever worn to the limit
4
*
Rear brake

Check operation and correct if necessary.

Check fluid level and ATV for fluid leakage, and
correct if necessary.
√√√√√

Replace brake pads. Whenever worn to the limit
5
*
Brake hoses

Check for cracks or other damage, and replace if
necessary.
√√√√

Replace. Every 4 years
6
*
Parking brake

Check operation and adjust if necessary.
√√√√√
7
*
Wheels


Check runout and for damage, and replace if nec-
essary.
√ √√√
8
*
Tires


Check tread depth and for damage, and replace if
necessary.

Check air pressure and balance, and correct if
necessary.
√ √√√
9
*
Wheel hub bearings


Check for looseness or damage, and replace if
necessary.
√ √√√

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20 Engine oil

Change.

Check ATV for oil leakage, and correct if neces-
sary.
√ √√√
21Engine oil filter ele-
ment

Clean or replace if necessary.
√√√
22 Cooling system

Check coolant level and ATV for coolant leakage,
and correct if necessary.
√√√√√

Replace coolant. Every 2 years
23
*
Moving parts and
cables

Lubricate.
√√√√
24
*
Throttle lever hous-
ing and cable


Check operation and correct if necessary.

Check throttle cable free play and adjust if neces-
sary.

Lubricate throttle lever housing and cable.
√√√√√
25
*
Front and rear brake
switches

Check operation and correct if necessary.
√√√√√
26
*
Lights and switches

Check operation and correct if necessary.

Adjust headlight beams.
√√√√√
NO. ITEMCHECK OR MAINTENANCE
JOBINITIAL EVERY
Whichev-
er comes
firstmonth 1 3 6 6 12
km
(mi)320
(200)1300
(800)2500
(1600)2500
(1600)5000
(3200)
hours 20 80 160 160 320

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EBU23070
NOTE:


The air filter needs more frequent service if you are riding in unusually wet or dusty areas.

Hydraulic brake service

Regularly check and, if necessary, correct the brake fluid level.

Every two years replace the internal components of the brake master cylinders and calipers, and
change the brake fluid.

Replace the brake hoses every four years and if cracked or damaged.

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3. Tighten the locknut.
EBU24060
Valve clearance
The valve clearance changes with use, resulting in
improper air-fuel mixture and/or engine noise. To
prevent this from occurring, the valve clearance
must be adjusted by a Yamaha dealer at the inter-
vals specified in the periodic maintenance and lu-
brication chart.
EBU24130
Checking the front and rear brake pads
The front and rear brake pads must be checked for
wear at the intervals specified in the periodic main-
tenance and lubrication chart.
EBU27711
Front brake pads
Each brake pad is provided with wear indicator
grooves, which allow you to check the brake pad
wear without having to disassemble the brake. To
check the brake pad wear, check the wear indica-
tor grooves. If a brake pad has worn to the point
that the wear indicator grooves are almost in con-
tact with the disc plate, have a Yamaha dealer re-
place the brake pads as a set.
1. Locknut
2. Throttle cable free play adjusting bolt
3. Throttle lever free play
3 2
1
(a)(b)

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NOTE:

The wheels need to be removed to check the
brake pads. (See page 8-50.)
EBU27721
Rear brake pads
Each brake pad is provided with wear indicator
grooves, which allow you to check the brake pad
wear without having to disassemble the brake. To
check the brake pad wear, check the wear indica-
tor grooves. If a brake pad has worn to the point
that the wear indicator grooves are almost in con-
tact with the disc plate, have a Yamaha dealer re-place the brake pads as a set.
EBU26831
Checking the brake fluid level
Insufficient brake fluid may allow air to enter the
brake system, possibly causing it to become inef-
fective.
Before riding, check that the brake fluid is above
the minimum level mark and replenish if neces-
sary. A low brake fluid level may indicate worn
brake pads and/or brake system leakage. If the
brake fluid level is low, be sure to check the brake
pads for wear and the brake system for leakage.
1. Wear indicator groove
1

1. Wear indicator groove1

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Front brake Rear brake
NOTE:
To check the rear brake fluid level, remove the
seat. (See page 4-11.)
If the rear brake fluid level is low, replenish as fol-
lows.
1. Remove the brake fluid reservoir bracket bolt.
1. Minimum level mark
1

1. Minimum level mark
1

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2. Pull the brake fluid reservoir out to the side as
shown.CAUTION:
ECB00780
Do not tilt the rear brake fluid reservoir exces-
sively when removing or installing the rear
brake fluid reservoir. Also do not twist or pull
the hose of the reservoir.
3. Remove the brake fluid reservoir cap, and
then refill with brake fluid.
4. Install the brake fluid reservoir cap.
5. Insert the projection on the brake fluid reser-
voir bracket into the hole in the frame.
1. Bolt
1

1. Brake fluid reservoir cap
1