2002 YAMAHA YZ125LC brake

5-13
CHASFRONT BRAKE AND REAR BRAKE
Extent of removal Order Part name Q’ty Remarks
MASTER CYLINDER DISASSEMBLY
1Master cylinder cap 1
2Diaphragm 1
3Master cylinder boot 1
4Circlip 1 Use a long nose circlip pliers.
5Plain washer 1
6Push rod 1
7Master cylinder kit 1
EC5A8300
MASTER CYLINDER DISASSEMBLY
AFront
BRear
Extent of removal:1Front master cylinder disassembly2Rear master cylinder disassembly
1
1
2
2
2 Nm (0.2 m•kg, 1.4 ft•lb)
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5-14
CHASFRONT BRAKE AND REAR BRAKE
EC5A3000
REMOVAL POINTS
EC5A3100
Brake fluid
1. Remove:
[Front]
9Master cylinder cap 1
[Rear]
9Reservoir tank cap 1
9Protector
NOTE:
Do not remove the diaphragm.
AFront
BRear
2. Connect the transparent hose 1to the
bleed screw 2and place a suitable contain-
er under its end.
AFront
BRear
3. Loosen the bleed screw and drain the brake
fluid while pulling the lever in or pushing
down on the pedal.
cC
9
Do not reuse the drained brake fluid.
9Brake fluid may erode painted surfaces
or plastic parts. Always clean up spilled
fluid immediately.
EC533301
Caliper piston
1. Remove:
9Caliper piston
Use compressed air and proceed carefully.
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9
Cover piston with rag and use extreme cau-
tion when expelling piston from cylinder.
9Never attempt to pry out piston.
AFront
BRear
Caliper piston removal steps:
9Insert a piece of rag into the caliper to
lock one caliper.
9Carefully force the piston out of the
caliper cylinder with compressed air.
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5-15
CHASFRONT BRAKE AND REAR BRAKE
EC533402
Piston seal kit
1. Remove:
9Dust seal 1
9Piston seal 2
NOTE:
Remove the piston seals and dust seals by
pushing them with a finger.
cC
Never attempt to pry out piston seals and
dust seals.
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Replace the piston seals and dust seals
whenever a caliper is disassembled.
AFront
BRear
EC5A4000
INSPECTION
EC534112
Master cylinder
1. Inspect:
9Master cylinder inner surface a
Wear/ScratchesReplace master cylinder
assembly.
StainsClean.
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Use only new brake fluid.
AFront
BRear
2. Inspect:
9Diaphragm 1
Crack/DamageReplace.
AFront
BRear
3. Inspect:
9Master cylinder piston 1
9Master cylinder cup 2
Wear/Damage/Score marksReplace master
cylinder kit.
AFront
BRear
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5-16
CHASFRONT BRAKE AND REAR BRAKE
EC534214
Caliper
1. Inspect:
9Caliper cylinder inner surface a
Wear/Score marksReplace caliper as-
sembly.
AFront
BRear
2. Inspect:
9Caliper piston 1
Wear/Score marksReplace caliper piston
assembly.
w
Replace the piston seals and dust seals 2 2
whenever a caliper is disassembled.
EC534301
Brake hose
1. Inspect:
9Brake hose 1
Crack/DamageReplace.
EC5A5000
ASSEMBLY AND INSTALLATION
w
9
All internal parts should be cleaned in
new brake fluid only.
9Internal parts should be lubricated with
brake fluid when installed.
9Replace the piston seals and dust seals
whenever a caliper is disassembled.
EC5A5800
Caliper piston
1. Clean:
9Caliper
9Piston seal
9Dust seal
9Caliper piston
Clean them with brake fluid.
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5-17
CHASFRONT BRAKE AND REAR BRAKE
2. Install:
9Piston seal 1
9Dust seal 2
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Always use new piston seals and dust
seals.
NOTE:
Fit the piston seals and dust seals onto the slot
on caliper correctly.
AFront
BRear
3. Install:
9Caliper piston 1
NOTE:
Apply the brake fluid on the piston wall.
cC
9
For the front caliper, install the piston
with its depressed side a a
facing the
caliper.For the rear caliper, install the pis-
ton with its shallow depressed side b b
facing the caliper.
9Never force to insert.
AFront
BRear
EC5A5700
Front caliper
1. Install:
9Pad support 1
9Brake pad 2
9Pad pin 3
NOTE:
9Install the brake pads with their projections
ainto the caliper recesses b.
9Temporarily tighten the pad pin at this point.
Aq
q
a
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5-18
CHASFRONT BRAKE AND REAR BRAKE
3. Install:
9Brake hose holder 1
9Caliper 2
9Bolt (caliper) 3
NOTE:
Fit the brake hose holder cut aover the projec-
tion bon the front fork and clamp the brake
hose.
4. Tighten:
9Pad pin 4
5. Install:
9Pad pin plug 5
EC5A5120
Rear caliper
1. Install:
9Pad support 1
9Brake pad 2
9Pad pin 3
NOTE:
9Install the brake pads with their projections
ainto the caliper recesses b.
9Temporarily tighten the pad pin at this point.
2. Install:
9Copper washer 1
9Union bolt 2
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Always use new copper washers.
cC
Install the brake hose so that its pipe por-
tion a a
directs as show and lightly touches
the projection b b
on the caliper.
30 Nm (3.0 m•kg, 22 ft•lb)
23 Nm (2.3 m•kg, 17 ft•lb)
18 Nm (1.8 m•kg, 13 ft•lb)
3 Nm (0.3 m•kg, 2.2 ft•lb)
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5-19
CHASFRONT BRAKE AND REAR BRAKE
2. Install:
9Disc cover 1
9Bolt (disc cover) 2
3. Install:
9Copper washer 1
9Brake hose 2
9Union bolt 3
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Always use new copper washers.
cC
Install the brake hose to the caliper with
the paint a a
on the pipe facing the caliper
and with the pipe contacting the caliper
projection b b
.
7 Nm (0.7 m•kg, 5.1 ft•lb)
30 Nm (3.0 m•kg, 22 ft•lb)
4. Install:
9Caliper 1
9Rear wheel 2
Refer to “FRONT WHEEL AND REAR
WHEEL” section.
5. Tighten:
9Pad pin 3
6. Install:
9Pad pin plug 4
18 Nm (1.8 m•kg, 13 ft•lb)
3 Nm (0.3 m•kg, 2.2 ft•lb)
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5-20
CHASFRONT BRAKE AND REAR BRAKE
EC5A5220
Master cylinder kit
1. Clean:
9Master cylinder
9Master cylinder kit
Clean them with brake fluid.
2. Install:
9Master cylinder cup (primary) 1
9Master cylinder cup (secondary) 2
To master cylinder piston 3.
NOTE:
Apply the brake fluid on the master cylinder cup.
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After installing, cylinder cup should be in-
stalled as shown direction. Wrong installa-
tion cause improper brake performance.
AFront
BRear
3. Install:
9Spring 1
To master cylinder piston 2.
NOTE:
Install the spring at the smaller dia. side.
AFront
BRear
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