2003 YAMAHA TTR125 brake

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

5 - 26
CHASREAR WHEEL AND REAR BRAKE
REMOVAL POINTS
EC523101
Rear wheel
1. Remove:
Wheel 1
NOTE:
Push the wheel forward and remove the drive
chain 2.
EC513201
Wheel bearing (if necessary)
1. Remove:
Bearing 1
NOTE:
Remove the bearing using a general bearing
puller 2.
INSPECTION
EC514100
Wheel
1. Measure:
Wheel runout
Out of limit → Repair/replace.
2. Inspect:
Bearing
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:
Wheel axle bends
Out of specification → Replace.
Use the dial gauge 1.
Wheel axle bending limit:
0.5 mm (0.020 in)

5 - 27
CHASREAR WHEEL AND REAR BRAKE
NOTE:
The bending value is shown by one half of the
dial gauge reading.
WARNING
Do not attempt to straighten a bent axle.
Drum brake
1. Inspect:
Brake shoe lining surface
Glazed areas → Polish.
Use coarse sand paper.
NOTE:
After polishing, wipe the polished particles with
a cloth.
2. Measure:
Brake shoe lining thickness a
Out of specification → Replace.
NOTE:
Replace the brake shoes and springs as a set
if either is worn to the limit.
Brake shoe lining thickness:
Standard
4.0 mm
(0.16 in)2.0 mm
(0.08 in)
3. Measure:
Brake drum inside diameter a
Out of specification → Replace.
Brake drum inside diameter:
Standard
110 mm
(4.33 in)111 mm
(4.37 in)

5 - 28
CHASREAR WHEEL AND REAR BRAKE
4. Inspect:
Brake drum inner surface.
Oil/scratches → Remove.
OilUse a rag soaked in lac-
quer thinner or a solvent.
ScratchesUse a emery cloth (lightly
and evenly polishing).
ASSEMBLY AND INSTALLATION
Brake shoe plate assembly
1. Install:
Brake camshaft 1
NOTE:
Apply the lithium soap base grease on the
brake camshaft.
2. Check:
Brake camshaft operation
Unsmooth operation → Repair.
3. Install:
Wear indicator plate 1
NOTE:
When installing the wear indicator plate to the
brake camshaft align the projection a on the
wear indicator plate with the slots b on the
brake camshaft.
4. Install:
Brake camshaft lever 1
NOTE:
Install the brake camshaft lever in relation to
the punch mark a as shown.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

5 - 29
CHASREAR WHEEL AND REAR BRAKE
5. Install:
Springs 1
Brake shoes 2
On brake shoe plate 3
NOTE:
Apply the lithium soap base grease on the
pivot pin.
When installing the springs and brake shoes,
take care not to damage the springs.
When replacing the brake shoes, replace the
springs as a set.
WARNING
Do not apply grease to the brake shoe lin-
ings.
New
Rear wheel
1. Install:
Wheel bearing 1
Spacer 2
Wheel bearing 3
Oil seal 4
NOTE:
Apply the lithium soap base grease on the oil
seal lip when installing.
Install the bearing with seal facing outward.
Use a socket that matches the outside diam-
eter of the race of the bearing.
Right side of bearing shall be installed first.
Install the oil seal with its manufacture’s
marks or numbers facing outward.
CAUTION:
Do not strike the inner race of the bearing.
Contact should be made only with the outer
race.
New

5 - 30
CHASREAR WHEEL AND REAR BRAKE
2. Install:
Wheel sprocket 1
Lock washers 2
Nut (wheel sprocket) 3
NOTE:
Tighten the nuts in stage, using a crisscross
pattern.
Bend the lock washer tab.
New
T R..43 Nm (4.3 m · kg, 31 ft · lb)
3. Install:
Collar (left)
Brake shoe plate assembly
Collar (right)
NOTE:
Apply the lithium soap base grease on the oil
seal lip.
4. Install:
Rear wheel
NOTE:
Make sure that the slot a on the brake shoe
plate with the stopper b on the swingarm.
5. Install:
Drive chain 1
NOTE:
Push the wheel 2 forward and install the drive
chain.
6. Install:
Drive chain puller (left) 1
Plain washer 2
Wheel axle 3
NOTE:
Apply the lithium soap base grease on the
wheel axle.
Insert the wheel axle from left side.

5 - 31
CHAS

REAR WHEEL AND REAR BRAKE
7. Install:

Drive chain puller (right)
1


Plain washer
2


Axle nut
3

NOTE:

Temporarily tighten the axle nut at this point.
8. Adjust:

Drive chain slack
a

Refer to “DRIVE CHAIN SLACK
ADJUSTMENT” section in the CHAP-
TER 3.
Drive chain slack:
35 ~ 50 mm (1.4 ~ 2.0 in)
9. Tighten:

Axle nut
1

T R..60 Nm (6.0 m · kg, 43 ft · lb)

10. Install:

Spring
1


Brake rod
2


Pin
3


Wing nut
4

On brake camshaft lever
5
.
11. Adjust:

Brake pedal free play
Refer to “REAR BRAKE ADJUST-
MENT” section in the CHAPTER 3.