brake YAMAHA TTR125 2002 Service Manual

5 - 17
CHASFRONT BRAKE (TT-R125LW)
ASSEMBLY AND INSTALLATION
WARNING
lAll internal parts should be cleaned in
new brake fluid only.
lInternal parts should be lubricated with
brake fluid when installed.
lReplace the brake caliper piston seals
and brake caliper dust seals whenever a
brake caliper is disassembled.
Brake caliper piston
1. Clean:
lBrake caliper
lBrake caliper piston seal
lBrake caliper dust seal
lBrake caliper piston
Clean them with brake fluid.
2. Install:
lBrake caliper piston seal 1
lBrake caliper dust seal 2
WARNING
Always use new brake caliper piston seals
and brake caliper dust seals.
NOTE:
Fit the brake caliper piston seals and brake
caliper dust seals onto the slot on brake cali-
per correctly.
New
New
3. Install:
lBrake caliper piston 1
NOTE:
Apply the brake fluid on the brake caliper pis-
ton wall.
CAUTION:
lInstall the brake caliper piston with its
shallow depressed side a facing the
brake caliper.
lNever force to insert.
Brake caliper
1. Install:
lSleeve boot 1.
On brake caliper bracket 2.

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CHASFRONT BRAKE (TT-R125LW)
2. Install:
lPin boot 1
On brake caliper 2.
NOTE:
Apply the lithium soap base grease on the pin
boot inner surface.
3. Install:
lBrake caliper bracket 1
lBolt (brake caliper bracket) 2
lBrake pad 3
T R..30 Nm (3.0 m · kg, 22 ft · lb)
4. Install:
lBrake caliper 1
NOTE:
lApply the lithium soap base grease on the
guide pin 2.
lInstall the brake caliper into the guide pin
and turn it clockwise.
5. Install:
lBrake caliper support bolt 1
NOTE:
Apply the lithium soap base grease on the
brake caliper support bolt.
T R..22 Nm (2.2 m · kg, 16 ft · lb)
Brake master cylinder kit
1. Clean:
lBrake master cylinder
lBrake master cylinder kit
Clean them with brake fluid.

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CHASFRONT BRAKE (TT-R125LW)
2. Install:
lBrake master cylinder cup (primary) 1
lBrake master cylinder cup (secondary) 2
On brake master cylinder piston 3.
NOTE:
Apply the brake fluid on the brake master cyl-
inder cup.
WARNING
After installing, cylinder cup should be
installed as shown direction. Wrong instal-
lation cause improper brake performance.
3. Install:
lSpring 1
On brake master cylinder piston 2.
NOTE:
Install the spring at the smaller diameter side.
4. Install:
lBrake master cylinder kit 1
lWasher 2
lCirclip 3
lBrake master cylinder boot 4
On brake master cylinder 5
NOTE:
lApply the brake fluid on the brake master
cylinder kit.
lWhen installing the circlip, use a long nose
circlip pliers.

5 - 20
CHAS
Brake master cylinder
1. Install:
lBrake master cylinder 1
lBrake master cylinder bracket 2
lBolt (brake master cylinder bracket) 3
NOTE:
lInstall the brake master cylinder bracket so
that the arrow mark a face upward.
lFirst tighten the bolts on the upper side of the
brake master cylinder bracket, and then
tighten the bolts on the lower side.
2. Install:
lBrake lever 1
lSpring 2
lBolt (brake lever) 3
lNut (brake lever) 4
NOTE:
lApply the lithium soap base grease on the
bolt and brake lever sliding surface.
lApply the molybdenum disulfide grease on
the tip of the adjuster bolt.
T R..9 Nm (0.9 m · kg, 6.5 ft · lb)
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
Brake hose
1. Install:
lCopper washer 1
lBrake hose 2
lUnion bolt 3
WARNING
Always use new copper washers.
CAUTION:
Install the brake hose so that its pipe por-
tion a directs as show and lightly touches
the projection b on the brake caliper.
New
T R..26 Nm (2.6 m · kg, 19 ft · lb)
FRONT BRAKE (TT-R125LW)

5 - 21
CHAS
2. Pass the brake hose through the cable
guide 1.
3. Install:
lCopper washer 1
lJoint 2
lBrake hose 3
WARNING
Always use a new copper washer.
NOTE:
When turning the joint over the brake hose,
hold the brake hose so that it may not be
twisted.
New
T R..26 Nm (2.6 m · kg, 19 ft · lb)
T R..14 Nm (1.4 m · kg, 10 ft · lb)
4. Install:
lBrake hose holder 1
lBolt (brake hose holder ) 2
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
FRONT BRAKE (TT-R125LW)

5 - 22
CHAS
Brake fluid
1. Fill:
lBrake fluid
Until the fluid level reaches “LOWER”
level line a.
WARNING
lUse only the designated quality brake
fluid:
otherwise, the rubber seals may deterio-
rate, causing leakage and poor brake per-
formance.
lRefill with the same type of brake fluid;
mixing fluids may result in a harmful chem-
ical reaction and lead to poor performance.
lBe careful that water does not enter the
brake master cylinder when refilling.
Water will significantly lower the boiling
point of the fluid and may result in vapor
lock.
CAUTION:
Brake fluid may erode painted surfaces or
plastic parts. Always clean up spilled fluid
immediately.
Recommended brake fluid:
DOT #4
2. Air bleed:
lBrake system
Refer to “BRAKE SYSTEM AIR
BLEEDING” section in the CHAPTER
3.
3. Inspect:
lBrake fluid level
Fluid at lower level ® Fill up.
Refer to “BRAKE FLUID LEVEL
INSPECTION” section in the CHAP-
TER 3.
FRONT BRAKE (TT-R125LW)

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CHAS
4. Install:
lDiaphragm
lBrake master cylinder cap 1
lScrew (brake master cylinder cap) 2
CAUTION:
After installation, while pulling in the lever,
check whether there is any brake fluid leak-
ing where the union bolts are installed
respectively at the brake master cylinder
and brake caliper.
T R..2 Nm (0.2 m · kg, 1.4 ft · lb)
FRONT BRAKE (TT-R125LW)

5 - 24
CHAS
REAR WHEEL AND REAR BRAKE
Extent of removal:1 Rear wheel removal 2 Wheel bearing removal
3 Brake shoe plate assembly removal and disassembly
Extent of removal Order Part name Q’ty Remarks
Preparation for removalREAR WHEEL AND DRUM
BRAKE
Hold the machine by placing the
suitable stand under the engine.
WARNING
Support the machine securely so there is nodanger of it falling over.
1 Brake rod 1
2 Axle nut 1
3 Drive chain puller (right) 1
4 Wheel axle 1
5 Drive chain puller (left) 1
6 Drive chain 1
7 Rear wheel 1 Refer to “REMOVAL POINTS”.
8 Collar (right) 1
9 Brake shoe plate assembly 1
10Collar (left)
1
231
REAR WHEEL AND REAR BRAKE

5 - 25
CHAS
Extent of removal Order Part name Q’ty Remarks
11 Nut (wheel sprocket) 4
12 Wheel sprocket 1
13 Oil seal 1
14 Wheel bearing 2 Refer to “REMOVAL POINTS”.
15 Spacer 1
16 Brake shoe 2
17 Spring 2
18 Brake camshaft lever 1
19 Wear indicator plate 1
20 Brake camshaft 1
21 Brake shoe plate 1
3
2
REAR WHEEL AND REAR BRAKE

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CHASREAR WHEEL AND REAR BRAKE
REMOVAL POINTS
EC523101
Rear wheel
1. Remove:
lWheel 1
NOTE:
Push the wheel forward and remove the drive
chain 2.
EC513201
Wheel bearing (if necessary)
1. Remove:
lBearing 1
NOTE:
Remove the bearing using a general bearing
puller 2.
INSPECTION
EC514100
Wheel
1. Measure:
lWheel runout
Out of limit ® Repair/replace.
2. Inspect:
lBearing
Rotate inner race with a finger.
Rough spot/seizure ® Replace.
NOTE:
Replace the bearings, oil seal and wheel collar
(wheel sprocket side) as a set.
Wheel runout limit:
Radial 1: 2.0 mm (0.08 in)
Lateral 2: 2.0 mm (0.08 in)
EC514200
Wheel axle
1. Measure:
lWheel axle bends
Out of specification ® Replace.
Use the dial gauge 1.
Wheel axle bending limit:
0.5 mm (0.020 in)