2016 YAMAHA WR 450F brake fluid

PERIODIC MAINTENANCE
3-7
BRAKESAdjust lever posi-
tion and pedal
height
Lubricate pivot
point
Check brake disc
surface
Check fluid level
and leakage
Retighten brake
disc bolts, caliper
bolts, master cylin-
der bolts and union
bolts
Replace pads
Replace brake flu-
id Every one year
FRONT FORKS Inspect and adjust
Replace oil Yamaha Suspension Oil S1
Replace oil seal
FRONT FORK OIL
SEAL AND DUST
SEAL Clean and lube Lithium-soap-based grease
PROTECTOR
GUIDE
Replace
REAR SHOCK AB-
SORBER (After
rain
ride)
Inspect and adjust
Lube Molybdenum disulfide grease
Retighten
DRIVE CHAIN
GUARD AND ROLL-
ERS
Inspect
DRIVE CHAIN
STOPPER Inspect ITEM
After
break- in Every
race Every
third (or
500
km) Every
fifth (or
1,000 km) As re-
quired Remarks

CHASSIS
3-25
EAS2GC1101
CHASSIS
EAS2GC1102BLEEDING THE BRAKE SYSTEMEWA
WARNING
Bleed the brake system whenever:
• The system is disassembled.
• A brake hose is loosened, disconnected, or replaced.
• The brake fluid level is very low.
• Brake operation is faulty.
1. Remove: • Brake master cylinder cap
• Reservoir diaphragm
• Reservoir float (front brake)
• Protector (rear brake)
TIP
• Be careful not to spill any brake fluid or allow the reservoir to overflow.
• Make sure that there is enough brake fluid be-
fore applying the brake. Ignoring this precau-
tion could allow air to enter the brake system,
considerably lengthening the bleeding proce-
dure.
• If bleeding is difficult, it may be necessary to let the brake fluid settle for a few hours. Re-
peat the bleeding procedure when the tiny
bubbles in the hose have disappeared.
2. Bleed the brake system.
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a. Fill the reservoir to the proper level with the recommended brake fluid.
b. Install the reservoir diaphragm.
c. Connect the plastic hose “1” to the bleed screw “2” securely, and place a container
under the end of the plastic hose. d. Slowly apply the brake several times.
e. Fully pull the brake lever or fully press down
the brake pedal and hold it in position.
f. Loosen the bleed screw.
TIP
Loosening the bleed screw will release the
pressure in the brake caliper and cause the
brake lever to contact the throttle grip or the
brake pedal to fully extend.
g. Tighten the bleed screw and then release the brake lever or brake pedal.
h. Repeat steps (d) to (g) until all of the air bub- bles have disappeared from the brake fluid
in the plastic hose.
TIP
During the procedure, keep adding brake fluid
to the reservoir.
ECA
NOTICE
• Wipe off any brake fluid on the brake discs, tires, wheels, etc.
• Brake fluid may erode painted surfaces or
plastic parts. Always clean up spilled fluid
immediately.
i. Tighten the bleed screw.
j. Pour brake fluid to the reservoir up to the specified level.
Refer to “CHECKING THE BRAKE FLUID
LEVEL” on page 3-30.
EWA
WARNING
After bleeding the hydraulic brake system,
check the brake operation.
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1
2
A
A. Front
B. Rear
Bleed screw
6 Nm (0.6 m·kgf, 4.3 ft·lbf)
2
1B
T R..

CHASSIS
3-26
EAS2GC1103CHECKING THE BRAKE HOSE
1. Check:• Brake hose “1”Cracks/damage/wear  Replace.
2. Check: • Brake hose clamp
Loose connection  Tighten the clamp bolt.
3. Stand the vehicle upright and apply the front brake and the rear brake several times.
4. Check: • Brake hosesBrake fluid leaks  Replace the damaged
brake hose.
Refer to “FRONT BRAKE” on page 5-13.
Refer to “REAR BRAKE” on page 5-23.
EAS2GC1104ADJUSTING THE FRONT BRAKE
1. Check: • Brake lever position “a” 2. Remove:
• Brake lever cover
3. Adjust: • Brake lever position
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a. Loosen the locknut “1”.
b. Turn the adjusting bolt “2” in direction “a” or “b” until the specified brake lever position is
obtained.
c. Tighten the locknut.
EWA13050
WARNING
A soft or spongy feeling in the brake lever
can indicate the presence of air in the brake
system. Before the vehicle is operated, the
air must be removed by bleeding the brake
system. Air in the brake system will consid-
erably reduce braking performance.
ECA13490
NOTICE
After adjusting the brake lever position,
make sure there is no brake drag.
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4. Install: • Brake lever cover
A. Front
B. Rear
Brake lever position95 mm (3.74 in)
Extent of adjustment 86–105 mm (3.39–4.13 in)
1
1
Direction “a”Brake lever position is increased.
Direction “b” Brake lever position is decreased.
Locknut5 Nm (0.5 m·kgf, 3.6 ft·lbf)
a
b
T R..

CHASSIS
3-28
c. Remove the brake caliper “3” from the front fork.
d. Remove the pad pin and brake pads “4”.
e. Connect the plastic hose “5” to the bleed screw “6” and place a container under the
end of the plastic hose.
f. Loosen the bleed screw and push the brake caliper piston in.
EWA
WARNING
Do not reuse the drained brake fluid.
g. Tighten the bleed screw.
h. Install the brake pads “7” and the pad pin.
TIP
• Install the brake pads with their projections “a” into the brake caliper recesses “b”.
• Temporarily tighten the pad pin at this point. i. Install the brake caliper “8” and tighten the
pad pin “9”.
j. Install the pad pin plug “10”.
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3. Check: • Brake fluid levelRefer to “CHECKING THE BRAKE FLUID
LEVEL” on page 3-30.
4. Check: • Brake lever operation
A softy or spongy feeling  Bleed the brake
system.
Refer to “BLEEDING THE BRAKE SYS-
TEM” on page 3-25.
Bleed screw
6 Nm (0.6 m·kgf, 4.3 ft·lbf)
3
2
4
6
5
T R..
Bolt (brake caliper)23 Nm (2.3 m·kgf, 17 ft·lbf)
Pad pin 17 Nm (1.7 m·kgf, 12 ft·lbf)
Pad pin plug 2.5 Nm (0.25 m·kgf, 1.8 ft·lbf)
7
a
b
T R..
8
9
T R..
10

CHASSIS
3-29
EAS2GC1107CHECKING THE REAR BRAKE PADS
1. Measure:• Brake pad thickness “a”Out of specification  Replace as a set.
TIP
The pads worn up to the indicator “b” grooves
mean that the brake pad thickness limit is
reached.
2. Replace:
• Brake pads
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a. Remove the protector “1” and the pad pin
plug “2”.
b. Loosen the pad pin “3”.
c. Remove the rear wheel “4” and the brake caliper “5”.
Refer to “REAR WHEEL” on page 5-9. d. Remove the pad pin “6” and the brake pads
“7”.
e. Connect the plastic hose “8” to the bleed screw “9” and place a container under the
end of the plastic hose.
f. Loosen the bleed screw and push the brake caliper piston in.EWA
WARNING
Do not reuse the drained brake fluid.
g. Tighten the bleed screw.
h. Install the brake pad “10” and the pad pin “11”.
TIP
• Install the brake pads with their projections “a” into the brake caliper recesses “b”.
• Temporarily tighten the pad pin at this point.
Brake pad lining thickness
6.4 mm (0.25 in)
Limit 1.0 mm (0.04 in)
b a
a
1
2
3
4
5
Bleed screw 6 Nm (0.6 m·kgf, 4.3 ft·lbf)
7
6
9
8
T R..
10
11
a
b

CHASSIS
3-30
i. Install the brake caliper “12” and the rear wheel “13”.
Refer to “REAR WHEEL” on page 5-9.
j. Tighten the pad pin “14”.
k. Install the pad pin plug “15” and the protector “16”.
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3. Check:• Brake fluid levelRefer to “CHECKING THE BRAKE FLUID
LEVEL” on page 3-30.
4. Check: • Brake pedal operationA softy or spongy feeling  Bleed the brake
system.
Refer to “BLEEDING THE BRAKE SYS-
TEM” on page 3-25.
EAS2GC1108CHECKING THE REAR BRAKE PAD INSU-
LATOR
1. Remove: • Brake padsRefer to “REAR BRAKE” on page 5-23. 2. Check:
• Rear brake pad insulator “1”Damage  Replace.
EAS2GC1109CHECKING THE BRAKE FLUID LEVEL
1. Stand the vehicle upright on a level surface.
TIP
In order to ensure a correct reading of the brake
fluid level, make sure that the top of the brake
fluid reservoir is horizontal.
2. Check:
• Brake fluid levelThe minimum level mark “a” or below 
Add.
EWA
WARNING
• Use only the designated brake fluid. Other brake fluids may cause the rubber seals to
deteriorate, causing leakage and poor
brake performance.
• Refill with the same type of brake fluid that
is already in the system. Mixing brake flu-
ids may result in a harmful chemical reac-
tion, leading to poor brake performance.
Pad pin
17 Nm (1.7 m·kgf, 12 ft·lbf)
Pad pin plug 2.5 Nm (0.25 m·kgf, 1.8 ft·lbf)
Bolt (protector) 7 Nm (0.7 m·kgf, 5.1 ft·lbf)
T R..
13
14
12
T R..
15 16
Specified brake fluidDOT 4
A. Front brake
B. Rear brake

CHASSIS
3-31
• When refilling, be careful that water does not enter the brake fluid reservoir. Water
will significantly lower the boiling point of
the brake fluid and could cause vapor
lock.
ECA
NOTICE
Brake fluid may damage painted surfaces
and plastic parts. Therefore, always clean
up any spilt brake fluid immediately.
EAS2GC1110ADJUSTING THE DRIVE CHAIN SLACKECA
NOTICE
A drive chain that is too tight will overload
the engine and other vital parts, and one
that is too loose can skip and damage the
swingarm or cause an accident. Therefore,
keep the drive chain slack within the speci-
fied limits.
1. Use a suitable stand to raise the rear wheel off the ground.
EWA
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
2. Shift the transmission into the neutral posi-
tion.
3. Pull the drive chain up above the drive chain guide installation bolt with a force of about
50 N (5.0 kgf, 36 lbf).
4. Check: • Drive chain slack “a”
Out of specification  Regulate.
TIP
Measure drive chain slack between the drive
chain guide and the bottom of the chain as
shown. 5. Adjust:
• Drive chain slack
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a. Loosen the wheel axle nut “1”.
b. Loosen both locknuts “2”.
c. Turn the adjusting bolt “3” in direction “a” or “b” until the specified drive chain slack is ob-
tained.
TIP
• To maintain the proper wheel alignment, ad-just both sides evenly.
• Push the rear wheel forward to make sure that
there is no clearance between the swingarm
end plates and the ends of the swingarm.
d. Tighten the locknut.
e. Tighten the wheel axle nut.
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EAS2GC1111CHECKING THE FRONT FORK LEGS
1. Stand the vehicle upright on a level surface.
EWA
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
2. Check: • Inner tubeDamage/scratches  Replace.
• Front fork leg (s) Oil leaks between inner tube and outer tube
 Replace the oil seal.
Drive chain slack (on a suitable
stand)
50.0–60.0 mm (1.97–2.36 in)
a
Direction “a”The drive chain slack decreases.
Direction “b” The drive chain slack increases.
Locknut21 Nm (2.1 m·kgf, 15 ft·lbf)
Wheel axle nut 125 Nm (12.5 m·kgf, 90 ft·lbf)
1
32
a
b
T R..
T R..

FRONT BRAKE
5-13
EAS2GC1167
FRONT BRAKE
Removing the front brake caliper
OrderPart name Q’tyRemarks
Brake fluid Drain.
Refer to “BLEEDING THE BRAKE SYSTEM”
on page 3-25.
1 Union bolt 1
2 Copper washers 2
3 Front brake hose 1
4 Brake pad pin plug 1
5 Brake pad pin 1
6 Brake pads 2
7 Brake pad spring 1
8 Front brake caliper assembly 1
9 Front brake caliper bracket 1
For installation, reverse the removal proce-
dure.
3
9
1
2
8
4
5
7
6
T.R.30 Nm (3.0 mlbf)
kgf, 22 ft
T.R.23 Nm (2.3 mlbf)
kgf, 17 ft
T.R.17 Nm (1.7 mlbf)
kgf, 12 ft
T.R.2.5 Nm (0.25 mlbf)
kgf, 1.8 ft
T.R.6 Nm (0.6 mlbf)
kgf, 4.3 ft