2014 YAMAHA YZ450F drain bolt

REAR BRAKE
4-25
EAS1SL1149INTRODUCTIONEWA14300
WARNING
If you need to disassemble the disc brake
components, observe the following precau
-
tions.
• Never disassemble the brake components
unless absolutely necessary.
• If there is any problem with connections
on the hydraulic brake system, perform
the following jobs.

Disassemble the brake system, drain the
brake fluid, and clean it. After that, add a
suitable amount of brake fluid. Then, bleed
it after reassembly.
• Use only brake fluid for washing internal
brake components.
• Use new brake fluid for cleaning the brake
components.
• Immediately wipe off the spilled brake fluid
to avoid damage to painted surfaces or
plastic parts.
• Handle brake fluid with special care not to
let it enter your eyes so that you may not
lost your eyesight.
• FIRST AID FOR BRAKE FLUID ENTERING
THE EYES:
• Flush with water for 15 minutes and get
immediate medical attention.
EAS1SL1150CHECKING THE REAR BRAKE DISC
1. Remove:
• Rear wheel
Refer to “REAR WHEEL” on page 4-7.
2. Check:
• Brake disc
Damage/galling  Replace.
3. Measure:
• Brake disc thickness
Measure the brake disc thickness at a few
different locations.
Out of specification  Replace.
Refer to “CHECKING THE FRONT BRAKE
DISC” on page 4-15.
4. Measure:
• Brake disc deflection
Out of specification  Correct the brake disc
deflection or replace the brake disc.
5. Adjust:
• Brake disc deflection
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a. Remove the brake disc.
b. Turn the mounted position of the brake disc
by one bolt hole.
c. Install the brake disc.
TIP
Tighten the brake disc bolts in stages and in a
crisscross pattern.
d. Measure the brake disc deflection.
e. If out of specification, repeat the adjustment
steps until the brake disc deflection is within
specification.
f. If the brake disc deflection cannot be
brought within specification, replace the
brake disc.
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6. Install:
• Rear wheel
Refer to “REAR WHEEL” on page 4-7.
EAS1SL1151
Brake disc thickness limit
3.5 mm (0.14 in)
Brake disc deflection limit
0.15 mm (0.0059 in)
Brake disc bolt
14 Nm (1.4 m·kgf, 10 ft·lbf)
LOCTITE®
T R..

REAR BRAKE
4-26
REMOVING THE REAR BRAKE CALIPER
TIP
Before disassembling the brake caliper, drain
the brake fluid from the entire brake system.
1. Remove:
• Union bolt
• Copper washers
• Brake hose
TIP
Put the end of the brake hose into a container
and pump out the brake fluid.
EAS1SL1152DISASSEMBLING THE REAR BRAKE CALI-
PER
1. Remove:
• Brake caliper piston “1”
• Brake caliper piston dust seal “2”
• Brake caliper piston seal “3”
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a. Blow compressed air into the brake hose
joint opening to force out the piston from the
brake caliper.
EWA13550
WARNING
• Cover the brake caliper piston with a cloth.
Be careful not to get injured when the pis
-
ton is expelled from the brake caliper.
• Do not use a screwdriver etc. for removing
the brake caliper piston.
b. Remove the brake caliper piston dust seal
and the brake caliper piston seal.
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EAS1SL1153CHECKING THE REAR BRAKE CALIPER
1. Check:
• Brake caliper piston “1”
Rust/scratches/wear  Replace the brake
caliper piston.
• Brake caliper cylinder “2”
Scratches/wear  Replace the brake cali-
per assembly.
• Brake caliper body “3”
Cracks/damage  Replace the brake cali-
per assembly.
• Brake fluid delivery passages
(brake caliper body)
Obstruction  Blow out with compressed
air.
EWA13610
WARNING
When the brake caliper is disassembled, re-
place the brake caliper piston seal and the
brake caliper piston dust seal with new
ones.
2. Check:
• Brake caliper bracket
Crack/damage  Replace.
EAS1SL1154ASSEMBLING THE REAR BRAKE CALIPEREWA13620
WARNING
• Before installation, clean and lubricate the
internal parts. Use new brake fluid for
cleaning and lubricating.
• Never use solvents on internal brake com-
ponents as they will cause the piston seals
to swell and distort.
• When the brake caliper is disassembled,
replace the brake caliper piston seal and
the brake caliper piston dust seal with new
ones.
EAS1SL1155
2
3
1
Recommended brake fluid
DOT 4
1 2
3

REAR BRAKE
4-28
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 pouring the brake fluid, be careful
that water does not enter the reservoir.
Water will significantly lower the boiling
point of the brake fluid and could cause
vapor lock.
ECA13540
NOTICE
Brake fluid may damage painted surfaces
and plastic parts. Therefore, always clean
up any spilt brake fluid immediately.
5. Bleed:
• Brake system
Refer to “BLEEDING THE BRAKE SYS-
TEM” on page 3-21.
6. Check:
• Brake fluid level
The minimum level mark “a” or below 
Add.
Refer to “CHECKING THE BRAKE FLUID
LEVEL” on page 3-26.
7. Check:
• Brake pedal operation
A softy or spongy feeling  Bleed the brake
system.
Refer to “BLEEDING THE BRAKE SYS-
TEM” on page 3-21.
EAS1SL1157
REMOVING THE REAR BRAKE MASTER
CYLINDER
TIP
Before removing the rear brake master cylin-
der, drain the brake fluid from the entire brake
system.
1. Remove:
• Union bolt
• Copper washers
• Brake hose
TIP
To drain any remaining brake fluid, place a con-
tainer under the master cylinder and the end of
the brake hose.
EAS1SL1158CHECKING THE REAR BRAKE MASTER
CYLINDER
1. Check:
• Brake master cylinder “1”
Damage/scratches/wear  Replace.
• Brake fluid delivery passages “2”
(brake master cylinder body)
Obstruction  Blow out with compressed
air.
2. Check:
• Brake master cylinder kit
Damage/wear  Replace
3. Check:
• Master cylinder reservoir cap
Crack/damage  Replace.
• Brake master cylinder reservoir diaphragm
holder
• Brake master cylinder reservoir diaphragm
Crack/damage  Replace.
4. Check:
• Brake hoses
Cracks/damage/wear  Replace.
EAS1SL1159
a
1
2

FRONT FORK
4-39
EAS1SL1166REMOVING THE FRONT FORK LEGS
1. Use a suitable stand to raise the front wheel
off the ground.
EWA13120
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
TIP
Record the adjusting screw setting position be-
fore loosening the adjuster and the base valve.
2. Loosen:
• Upper bracket pinch bolts
• Damper assembly
• Lower bracket pinch boltsEWA13120
WARNING
Before loosening the upper and lower
bracket pinch bolts, support the front fork
leg.
TIP
Before removing the front fork leg from the ve-
hicle, loosen the damper assembly “1” with the
cap bolt ring wrench “2.”
3. Remove:
• Front fork leg (s)
EAS1SL1167DISASSEMBLING THE FRONT FORK LEGS
1. Drain:
• Fork oil
2. Remove:
• Adjuster “1”
(from the inner tube)
TIP
• While compressing the inner tube “2”, set the
cap bolt ring wrench “4” between the inner
tube and locknut “3”.
• Hold the locknut and remove the adjuster.
ECA14180
NOTICE
Do not remove the locknut as the damper
rod may go into the damper assembly and
not be taken out.
3. Remove:
• Dust seal “1”
• Oil seal clip “2”
(with a flat-head screwdriver)ECA14180
NOTICE
Do not scratch the inner tube.
4. Remove:
• Inner tube “1”
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a. Push in slowly “a” the inner tube just before
it bottoms out and then pull it back quickly
“b”.
b. Repeat this step until the inner tube can be
pulled out from the outer tube.
Cap bolt ring wrench
90890-01501
YM-01501
12
Cap bolt ring wrench
90890-01501
YM-01501
1
234
1
2

WATER PUMP
6-6
2. Install:
• Dowel pin “1”
• Gasket “2”
3. Install:
• Water pump housing “1”
• Water pump housing bolt “2”
• Washer “3”
• Coolant drain bolt “4”
Water pump housing bolt
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Coolant drain bolt
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
New
21
1New
T R..
New
T R..
2
2
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