2016 YAMAHA YZ450F brake

CHASSIS
3-27
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.
i. Install the brake caliper “12” and the rear
wheel “13”.
Refer to “REAR WHEEL” on page 4-7.
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 level
Refer to “CHECKING THE BRAKE FLUID
LEVEL” on page 3-27.
4. Check:
• Brake pedal operation
A softy or spongy feeling  Bleed the brake
system.
Refer to “BLEEDING THE BRAKE SYS-
TEM” on page 3-22.
EASB111095CHECKING THE REAR BRAKE PAD INSU-
LATOR
1. Remove:
• Brake pads
Refer to “REAR BRAKE” on page 4-22.
2. Check:
• Rear brake pad insulator “1”
Damage  Replace.
EASB111096CHECKING 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. Bleed screw
6 Nm (0.6 m·kgf, 4.3 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)
Bolt (protector)
7 Nm (0.7 m·kgf, 5.1 ft·lbf)
T R..
10 11
a
b
T R..
13
14
12
T R..
15
16

CHASSIS
3-28
2. Check:
• Brake fluid level
The 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.
• 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.
EASB111097ADJUSTING THE DRIVE CHAIN SLACKECA13550
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.
EWA13120
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. Specified brake fluid
DOT 4
A. Front brake
B. Rear brake
Drive chain slack
50–60 mm (1.97–2.36 in)
Direction “a”
The drive chain slack decreases.
Direction “b”
The drive chain slack increases.
a

CHASSIS
3-29
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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EASB111098CHECKING 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 tube
Damage/scratches  Replace.
• Front fork leg (s)
Oil leaks between inner tube and outer tube
 Replace the oil seal.
3. Hold the vehicle upright and apply the front
brake.
4. Check:
• Front fork operation
Push down hard on the handlebar several
times and check if the front fork rebounds
smoothly.
Unsmooth operation  Correct or replace.
Refer to “FRONT FORK” on page 4-38.
EASB111099CHECKING THE FRONT FORK PROTEC-
TOR GUIDE
1. Check:
• Protector guide “1”
Out of specification  Replace.
TIP
The protector guide reaches the limit of its use
when it is worn down to the same height “a” as
of the outer tube circumference.
EASB111100CLEANING THE FRONT FORK OIL SEAL
AND DUST SEAL
1. Remove:
•Protector
• Dust seal “1”
ECA
NOTICE
Be careful not to damage the dust seal and
the inner tube by a driver. Locknut
21 Nm (2.1 m·kgf, 15 ft·lbf)
Wheel axle nut
135 Nm (13.5 m·kgf, 98 ft·lbf)
1
32
a
b
T R..
T R..1
a
1

CHASSIS
3-36
5. Install:
• Upper bracket
Refer to “STEERING HEAD” on page 4-51.
• Handlebar
Refer to “HANDLEBAR” on page 4-32.
EASB111111LUBRICATING THE LEVERS
1. Lubricate the pivoting points and metal-to-
metal moving parts of the following parts.
• Brake lever
•Clutch lever
EASB111112LUBRICATING THE PEDAL
1. Lubricate the pivoting point and metal-to-
metal moving parts of the pedal.Recommended lubricant
Silicone grease
Recommended lubricant
Lithium-soap-based grease
Recommended lubricant
Lithium-soap-based grease

4
CHASSIS
GENERAL CHASSIS........................................................................................ 4-1
REMOVING THE LEFT SIDE COVER ....................................................... 4-2
REMOVING THE SEAT ............................................................................. 4-2
REMOVING THE NUMBER PLATE ........................................................... 4-2
FRONT WHEEL................................................................................................ 4-3
REMOVING THE FRONT WHEEL............................................................. 4-4
CHECKING THE FRONT WHEEL ............................................................. 4-4
DISASSEMBLING THE FRONT WHEEL ................................................... 4-5
ASSEMBLING THE FRONT WHEEL ......................................................... 4-5
INSTALLING THE FRONT WHEEL ........................................................... 4-6
REAR WHEEL.................................................................................................. 4-7
REMOVING THE REAR WHEEL ............................................................... 4-8
CHECKING THE REAR WHEEL................................................................ 4-8
DISASSEMBLING THE REAR WHEEL ..................................................... 4-8
CHECKING AND REPLACING THE REAR WHEEL SPROCKET ............ 4-8
ASSEMBLING THE REAR WHEEL ........................................................... 4-9
INSTALLING THE REAR WHEEL............................................................ 4-10
FRONT BRAKE.............................................................................................. 4-12
INTRODUCTION ...................................................................................... 4-16
CHECKING THE FRONT BRAKE DISC .................................................. 4-16
REMOVING THE FRONT BRAKE CALIPER ........................................... 4-16
DISASSEMBLING THE FRONT BRAKE CALIPER................................. 4-16
CHECKING THE FRONT BRAKE CALIPER ........................................... 4-17
ASSEMBLING THE FRONT BRAKE CALIPER ....................................... 4-17
INSTALLING THE BRAKE CALIPER PISTON ........................................ 4-17
INSTALLING THE FRONT BRAKE CALIPER ......................................... 4-18
REMOVING THE FRONT BRAKE MASTER CYLINDER ........................ 4-19
CHECKING THE FRONT BRAKE MASTER CYLINDER......................... 4-19
ASSEMBLING THE FRONT BRAKE MASTER CYLINDER .................... 4-19
INSTALLING THE FRONT BRAKE MASTER CYLINDER....................... 4-20
REAR BRAKE................................................................................................ 4-22
INTRODUCTION ...................................................................................... 4-26
CHECKING THE REAR BRAKE DISC..................................................... 4-26
REMOVING THE REAR BRAKE CALIPER ............................................. 4-27
DISASSEMBLING THE REAR BRAKE CALIPER ................................... 4-27
CHECKING THE REAR BRAKE CALIPER .............................................. 4-27
ASSEMBLING THE REAR BRAKE CALIPER ......................................... 4-27
INSTALLING THE BRAKE CALIPER PISTON ........................................ 4-28
INSTALLING THE REAR BRAKE CALIPER ............................................ 4-28
REMOVING THE REAR BRAKE MASTER CYLINDER .......................... 4-29
CHECKING THE REAR BRAKE MASTER CYLINDER ........................... 4-29
ASSEMBLING THE REAR BRAKE MASTER CYLINDER....................... 4-30
INSTALLING THE REAR BRAKE MASTER CYLINDER ......................... 4-30

FRONT WHEEL
4-3
EASB111121
FRONT WHEEL
Removing the front wheel
Order Part name Q’ty Remarks
Use a suitable stand to raise the front wheel
off the ground.
1 Front wheel axle pinch bolt 4 Loosen.
2 Front wheel axle nut 1
3 Front wheel axle 1
4 Front wheel 1
5Collars 2
6Oil seals 2
7 Bearing 2
8 Brake disc 1
For installation, reverse the removal proce-
dure.
12 Nm (1.2 mkgf, 8.7 ftIbf)T.R
.
New
New
LT
LS
LS
LS
5
76
5 6 7
(6)
8
12
1 3
21 Nm (2.1 mkgf, 15 ftIbf)T.R.
21 Nm (2.1 mkgf, 15 ftIbf)T.R.
4
115 Nm (11.5 mkgf, 83 ftlbf)T.R.

FRONT WHEEL
4-5
EASB111124DISASSEMBLING THE FRONT WHEEL
1. Remove:
• Oil seals
• Bearings
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a. Clean the outside of the front wheel hub.
b. Remove the oil seals “1” with a flat-head
screwdriver.
TIP
To prevent damaging the wheel, place a rag “2”
between the screwdriver and the wheel sur-
face.
c. Remove the bearings with a bearing puller.
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EASB111125ASSEMBLING THE FRONT WHEEL
1. Install:
• Bearing (left side) “1”
• Spacer “2”
• Bearing (right side) “3”
• Oil seals “4”
TIP
• Apply the lithium-soap-based grease to the
bearing and the oil seal lip when installing.
• Left side of bearing shall be installed first.
• Install the oil seal with its manufacture’s
marks or numbers facing outward.
ECA
NOTICE
Install the bearing by pressing its outer race
parallel.
TIP
Use a socket “1” that matches the diameter of
the bearing outer race and that of the oil seal.
2. Install:
• Brake disc “1”
• Brake disc bolt “2”
TIP
Tighten the bolts in stages and in a crisscross
pattern.
12
New
Brake disc bolt
12 Nm (1.2 m·kgf, 8.7 ft·lbf)
LOCTITE®
4
3
2
1
4
New
New
1
T R..

FRONT WHEEL
4-6
3. Install:
• Collar “1”
TIP
Apply the lithium-soap-based grease on the oil
seal lip.
EASB111126INSTALLING THE FRONT WHEEL
1. Install:
• Front wheel
TIP
Install the brake disc “1” between the brake
pads “2” correctly.
2. Install:
• Front wheel axle “1”
TIP
Apply the lithium-soap-based grease to the
front wheel axle.3. Tighten:
• Front wheel axle nut “1”
ECA
NOTICE
Before tightening the front wheel axle nut,
push down hard on the handlebar(s) several
times and check if the front fork rebounds
smoothly.
4. Tighten:
• Front wheel axle pinch bolt “1”
1
LS
Front wheel axle nut
115 Nm (11.5 m·kgf, 83 ft·lbf)
Front wheel axle pinch bolt
21 Nm (2.1 m·kgf, 15 ft·lbf)
T R..
1
T R..
1 1