brake YAMAHA TW125 2003 User Guide

6-20
PERIODIC MAINTENANCE AND MINOR REPAIR
6 5. Loosen the locknut at the
crankcase.
6. To increase the clutch lever free
play, turn the adjusting nut in
direction a. To decrease the
clutch lever free play, turn the
adjusting nut in direction b.
7. Tighten the locknut at the clutch
lever and the crankcase.
21
ba
1. Locknut (crankcase)
2. Adjusting nut
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Adjusting the brake lever
free play
The brake lever free play should
measure 5–8 mm as shown.
Periodically check the brake lever
free play and, if necessary, adjust it
as follows.
1. Loosen the locknut at the brake
lever.
2. To increase the brake lever free
play, turn the adjusting bolt in
direction a. To decrease the
brake lever free play, turn the
adjusting bolt in direction b.
c12
a
b
1. Locknut
2. Adjusting bolt
c. Free play
3. Tighten the locknut.EW000099
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8After adjusting the brake lever
free play, check the free play
and make sure that the brake
is working properly.
8A soft or spongy feeling in the
brake lever can indicate the
presence of air in the
hydraulic system. If there is air
in the hydraulic system, have
a Yamaha dealer bleed the
system before operating the
motorcycle. Air in the
hydraulic system will diminish
the braking performance,
which may result in loss of
control and an accident.
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6-21
PERIODIC MAINTENANCE AND MINOR REPAIR
6
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Adjusting the brake pedal
position and free play
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It is advisable to have a Yamaha
dealer make these adjustments.
Brake pedal position
The top of the brake pedal should be
positioned approximately 30 mm
below the top of the footrest.
Periodically check the brake pedal
position and, if necessary, adjust it as
follows.
c
2 1
a
b
1. Locknut
2. Adjusting bolt
c. Brake pedal position
1. Loosen the locknut at the brake
pedal.
2. To raise the brake pedal, turn the
adjusting bolt in direction a. To
lower the brake pedal, turn the
adjusting bolt in direction b.
3. Tighten the locknut.
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After adjusting the brake pedal
position, the brake pedal free play
must be adjusted.
Brake pedal free play
The brake pedal free play should
measure 20–30 mm as shown.
Periodically check the brake pedal
free play and, if necessary, adjust it
as follows.
a
a. Brake pedal free play
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6-22
PERIODIC MAINTENANCE AND MINOR REPAIR
6 To increase the brake pedal free
play, turn the adjusting nut at the
brake rod in direction a. To
decrease the brake pedal free play,
turn the adjusting nut in direction b.
b
a1
1. Brake pedal free play adjusting nut
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8After adjusting the drive chain
slack or removing and
installing the rear wheel,
always check the brake pedal
free play.
8If proper adjustment cannot be
obtained as described, have a
Yamaha dealer make this
adjustment.
8After adjusting the brake pedal
free play, check the operation
of the brake light.
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Adjusting the rear brake light
switch
The rear brake light switch, which is
activated by the brake pedal, is prop-
erly adjusted when the brake light
comes on just before braking takes
effect. If necessary, adjust the brake
light switch as follows.
Turn the adjusting nut while holding
the rear brake light switch in place.
To make the brake light come on ear-
lier, turn the adjusting nut in direction
a. To make the brake light come on
later, turn the adjusting nut in direc-
tion b.
1
2
a
b
1. Rear brake light switch
2. Adjusting nut
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6-23
PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU00720
Checking the front brake
pads and rear brake shoes
The front brake pads and the rear
brake shoes must be checked for
wear at the intervals specified in the
periodic maintenance and lubrication
chart.
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Front brake pads
Each front 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 indicator grooves. If a
brake pad has worn to the point that
the wear indicator grooves have
almost disappeared, have a Yamaha
dealer replace the brake pads as a
set.
11
1. Brake pad wear indicator groove (×3)
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Rear brake shoes
The rear brake is provided with a
wear indicator, which allows you to
check the brake shoe wear without
having to disassemble the brake. To
check the brake shoe wear, check
the position of the wear indicator
while applying the brake. If a brake
shoe has worn to the point that the
wear indicator reaches the wear limit
line, have a Yamaha dealer replace
the brake shoes as a set.
2
1
1. Wear limit line
2. Wear indicator
FRONTREAR
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6-24
PERIODIC MAINTENANCE AND MINOR REPAIR
6
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Checking the brake fluid
level
Insufficient brake fluid may allow air
to enter the brake system, possibly
causing it to become ineffective.
Before riding, check that the brake
fluid is above the minimum level mark
and replenish if necessary. 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 leak-
age.
1
1. Minimum level mark
Observe these precautions:
8When checking the fluid level,
make sure that the top of the
brake fluid reservoir is level.
8Use only the recommended qual-
ity brake fluid, otherwise the rub-
ber seals may deteriorate, caus-
ing leakage and poor braking
performance.
8Refill with the same type of brake
fluid. Mixing fluids may result in a
harmful chemical reaction and
lead to poor braking perfor-
mance.
8Be careful that water does not
enter the brake fluid reservoir
when refilling. Water will signifi-
cantly lower the boiling point of
the fluid and may result in vapor
lock.8Brake fluid may deteriorate paint-
ed surfaces or plastic parts.
Always clean up spilled fluid
immediately.
8As the brake pads wear, it is nor-
mal for the brake fluid level to
gradually go down. However, if
the brake fluid level goes down
suddenly, have a Yamaha dealer
check the cause.
Recommended brake fluid:
DOT 4
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PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU03985
Changing the brake fluid
Have a Yamaha dealer change the
brake fluid at the intervals specified in
the NOTE after the periodic mainte-
nance and lubrication chart. In addi-
tion, have the oil seals of the brake
master cylinder and caliper as well as
the brake hose replaced at the inter-
vals listed below or whenever they
are damaged or leaking.
8Oil seals: Replace every two
years.
8Brake hose: Replace every four
years.
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Drive chain slack
The drive chain slack should be
checked before each ride and adjust-
ed if necessary.
To check the drive chain slack
1. Place the motorcycle on a level
surface and hold it in an upright
position.
NOTE:
When checking and adjusting the
drive chain slack, the motorcycle
should be positioned straight up and
there should be no weight on it.2. Shift the transmission into the
neutral position.
3. Move the rear wheel by pushing
the motorcycle to locate the tight-
est portion of the drive chain,
and then measure the drive
chain slack as shown.
4. If the drive chain slack is incor-
rect, adjust it as follows.
a
a. Drive chain slack
Drive chain slack:
35–60 mm
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PERIODIC MAINTENANCE AND MINOR REPAIR
6
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To adjust the drive chain slack
1. Loosen the brake pedal free play
adjusting nut.
2. Loosen the axle nut.
3. To tighten the drive chain, turn
the adjusting plate on each side
of the swingarm in direction a.
To loosen the drive chain, turn
the adjusting plate on each side
of the swingarm in direction b,
and then push the rear wheel for-
ward.
32
a
b
1
1. Brake pedal free play adjusting nut
2. Axle nut
3. Drive chain adjusting plate
NOTE:
Make sure that both adjusting plates
are in the same position for proper
wheel alignment.
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Improper drive chain slack will
overload the engine as well as
other vital parts of the motorcycle
and can lead to chain slippage or
breakage. To prevent this from
occurring, keep the drive chain
slack within the specified limits.
4. Tighten the axle nut to the speci-
fied torque.5. Adjust the brake pedal free play.
(See page 6-21 for brake pedal
free play adjustment proce-
dures.)
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After adjusting the brake pedal
free play, check the operation of
the brake light.
Tightening torque:
Axle nut:
90 Nm (9.0 m·kgf)
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PERIODIC MAINTENANCE AND MINOR REPAIR
6
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Damage to the outer sheath may
interfere with proper cable opera-
tion and will cause the inner cable
to rust. Replace a damaged cable
as soon as possible to prevent
unsafe conditions.
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Checking and lubricating the
throttle grip and cable
The operation of the throttle grip
should be checked before each ride.
In addition, the cable should be lubri-
cated or replaced at the intervals
specified in the periodic maintenance
chart.
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Checking and lubricating the
brake and shift pedals
The operation of the brake and shift
pedals should be checked before
each ride, and the pedal pivots
should be lubricated if necessary.
Recommended lubricant:
Lithium-soap-based grease
(all-purpose grease)
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6-29
PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU03164
Checking and lubricating the
brake and clutch levers
The operation of the brake and clutch
levers should be checked before
each ride, and the lever pivots should
be lubricated if necessary.
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Checking and lubricating the
sidestand
The operation of the sidestand
should be checked before each ride,
and the sidestand pivot and metal-to-
metal contact surfaces should be
lubricated if necessary.
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If the sidestand does not move up
and down smoothly, have a
Yamaha dealer check or repair it.
Recommended lubricant:
Lithium-soap-based grease
(all-purpose grease)
Recommended lubricant:
Lithium-soap-based grease
(all-purpose grease)
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PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU04282
Lubricating the rear
suspension
The pivoting points of the rear sus-
pension must be lubricated at the
intervals specified in the periodic
maintenance and lubrication chart.
1
1. Grease nipple (×2)
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Checking the front fork
The condition and operation of the
front fork must be checked as follows
at the intervals specified in the peri-
odic maintenance and lubrication
chart.
To check the condition
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Securely support the motorcycle
so that there is no danger of it
falling over.
Check the inner tubes for scratches,
damage and excessive oil leakage.To check the operation
1. Place the motorcycle on a level
surface and hold it in an upright
position.
2. While applying the front brake,
push down hard on the handle-
bars several times to check if the
front fork compresses and
rebounds smoothly.
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If any damage is found or the front
fork does not operate smoothly,
have a Yamaha dealer check or
repair it.
Recommended lubricant:
Lithium-soap-based grease
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