2015 YAMAHA WR 250F brake fluid

CHASSIS
3-24
EAS2GB2103
CHASSIS
EAS2GB2104BLEEDING 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 3-29.
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
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CHASSIS
3-25
EAS2GB2105CHECKING 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 hoses
Brake fluid leaks  Replace the damaged
brake hose.
Refer to “FRONT BRAKE” on page 5-13.
Refer to “REAR BRAKE” on page 5-23.
EAS2GB2106ADJUSTING 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.
EWA
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.
ECA
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 position
95 mm (3.74 in)
Extent of adjustment
76–97 mm (2.99–3.82 in)
1
1
Direction “a”
Brake lever position is increased.
Direction “b”
Brake lever position is decreased.
Locknut
5 Nm (0.5 m·kgf, 3.6 ft·lbf)
a
b
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CHASSIS
3-27
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 level
Refer to “CHECKING THE BRAKE FLUID
LEVEL” on page 3-29.
4. Check:
• Brake lever operation
A softy or spongy feeling  Bleed the brake
system.
Refer to “BLEEDING THE BRAKE SYS-
TEM” on page 3-24. Bleed screw
6 Nm (0.6 m·kgf, 4.3 ft·lbf)
3
2
4
6
5
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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
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8
9
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10

CHASSIS
3-28
EAS2GB2109CHECKING 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 (inner)
6.4 mm (0.25 in)
Limit
1.0 mm (0.04 in)
Brake pad lining thickness (outer)
6.4 mm (0.25 in)
Limit
1.0 mm (0.04 in)
ba
a
1 2
Bleed screw
6 Nm (0.6 m·kgf, 4.3 ft·lbf)
34
5
7 6
9
8
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CHASSIS
3-29
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 level
Refer to “CHECKING THE BRAKE FLUID
LEVEL” on page 3-29.
4. Check:
• Brake pedal operation
A softy or spongy feeling  Bleed the brake system.
Refer to “BLEEDING THE BRAKE SYS-
TEM” on page 3-24.
EAS2GB2110CHECKING THE REAR BRAKE PAD INSU-
LATOR
1. Remove:
• Brake pads
Refer to “REAR BRAKE” on page 5-23.
2. Check:
• Rear brake pad insulator “1”
Damage  Replace.
EAS2GB2111CHECKING 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 level
The minimum level mark “a” or below 
Add. 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)
10 11
a
b
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13
14
12
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15
16
Recommended brake fluid
DOT 4
A. Front brake
B. Rear brake

CHASSIS
3-30
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.
EAS2GB2112ADJUSTING 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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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.
Locknut
21 Nm (2.1 m·kgf, 15 ft·lbf)
Wheel axle nut
125 Nm (12.5 m·kgf, 90 ft·lbf)
a
1
32
a
b
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FRONT BRAKE
5-13
EAS2GB2169
FRONT BRAKE
Removing the front brake caliper
Order Part name Q’ty Remarks
Brake fluidDrain.
Refer to “BLEEDING THE BRAKE SYSTEM”
on page 3-24.
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 2
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

FRONT BRAKE
5-15
Removing the front brake master cylinder
Order Part name Q’ty Remarks
Brake fluidDrain.
Refer to “BLEEDING THE BRAKE SYSTEM”
on page 3-24.
1 Brake lever 1
2 Union bolt 1
3 Copper washers 2
4 Front brake hose 1
5 Brake master cylinder reservoir cap 1
6 Brake master cylinder reservoir diaphragm 1
7 Front brake master cylinder float 1
8 Front brake master cylinder holder 1
9 Front brake master cylinder 1
For installation, reverse the removal proce-
dure.
S1
23
4 5
68
9
S
7
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