brake YAMAHA YZ426F 2001 Owner's Guide

5 - 2
CHAS

EC598100
REAR WHEEL
Extent of removal:
1
Rear wheel removal
2
Wheel bearing removal
3
Break disc removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removal
REAR WHEEL REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING

Support the machine securely so there is no
danger of it falling over.
1 Nut (rear wheel axle) 1
2 Rear wheel axle 1
3 Chain puller 2
4 Rear wheel 1 Refer to “REMOVAL POINTS”.
5 Collar 2
6 Driven sprocket 1
7 Oil seal 2
8 Circlip 1
9 Bearing 2 Refer to “REMOVAL POINTS”.
10Brake disk
1
2
31
3

FRONT WHEEL AND REAR WHEEL

5 - 4
CHASFRONT WHEEL AND REAR WHEEL
EC514200
Wheel axle
1. Measure:
lWheel axle bends
Out of specification ® Replace.
Use the dial gauge 1.
NOTE:
The bending value is shown by one half of the
dial gauge reading.
WARNING
Do not attempt to straighten a bent axle.
Wheel axle bending limit:
0.5 mm (0.020 in)
EC594200
Brake disc
1. Measure:
lBrake disc deflection (only rear brake
disc)
Use the dial gauge 1.
Out of specification ® Inspect wheel
runout.
If wheel runout is in good condition,
replace the brake disc.
2. Measure:
lBrake disc thickness a
Out of limit ® Replace.
Disc deflection limit:
Standard
Rear —0.15 mm
(0.006 in)
Disc wear limit:
Standard
Front 3.0 mm (0.12 in) 2.5 mm (0.10 in)
Rear 4.0 mm (0.16 in) 3.5 mm (0.14 in)

5 - 5
CHASFRONT WHEEL AND REAR WHEEL
EC595000
ASSEMBLY AND INSTALLATION
EC595100
Front wheel
1. Install:
lBearing (left) 1
lSpacer 2
lBearing (right) 3
lOil seal 4
NOTE:
lApply the lithium soap base grease on the
bearing and oil seal lip when installing.
lUse a socket that matches the outside diam-
eter of the race of the bearing.
lLeft side of bearing shall be installed first.
lInstall the oil seal with its manufacture’s
marks or numbers facing outward.
ACHTUNG:CAUTION:
Do not strike the inner race of the bearing.
Contact should be made only with the outer
race.
2. Install:
lBrake disc 1
lBolt (brake disc) 2
NOTE:
Tighten the bolts in stage, using a crisscross
pattern.
New
T R..12 Nm (1.2 m · kg, 8.7 ft · lb)
3. Install:
lCollar 1
NOTE:
lApply the lithium soap base grease on the oil
seal lip.
lInstall the collars with their projections a
facing the wheel.
4. Install:
lWheel
NOTE:
Install the brake disc 1 between the brake
pads 2 correctly.

5 - 6
CHASFRONT WHEEL AND REAR WHEEL
5. Install:
lWheel axle 1
NOTE:
Apply the lithium soap base grease on the
wheel axle.
6. Install:
lNut (wheel axle) 1
T R..105 Nm (10.5 m · kg, 75 ft · lb)
7. Tighten:
lBolt (axle holder) 1
NOTE:
Before tightening the bolt, fit the wheel axle to
the axle holder by stroking the front fork sev-
eral times with the front brake applied.
8. Install:
lBrake hose 1
To brake hose holder 2.
NOTE:
Before tightening the bolt (brake hose holder),
pass the brake hose in front of the axle boss
a, then fit it into the hose groove b so that the
brake hose does not contact the nut (wheel
axle).
T R..23 Nm (2.3 m · kg, 17 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

5 - 7
CHASFRONT WHEEL AND REAR WHEEL
9. Install:
lHose cover 1
lPlain washer 2
lBolt [hose cover (M8)] 3
lBolt [hose cover (M6)] 4
T R..16 Nm (1.6 m · kg, 11 ft · lb)
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
EC5251A0
Rear wheel
1. Install:
lBearing (right) 1
lCirclip 2
lSpacer 3
lBearing (left) 4
lOil seal 5
NOTE:
lApply the lithium soap base grease on the
bearing and oil seal lip when installing.
lInstall the bearing with seal facing outward.
lUse a socket that matches the outside diam-
eter of the race of the bearing.
lRight side of bearing shall be installed first.
lInstall the oil seal with its manufacture’s
marks or numbers facing outward.
ACHTUNG:CAUTION:
Do not strike the inner race of the bearing.
Contact should be made only with the outer
race.
New
New
2. Install:
lBrake disc 1
lBolt (brake disc) 2
NOTE:
Tighten the bolts in stage, using a crisscross
pattern.
T R..14 Nm (1.4 m · kg, 10 ft · lb)

5 - 8
CHAS
3. Install:
lDriven sprocket 1
lBolt (driven sprocket) 2
lPlain washer (driven sprocket) 3
lNut (driven sprocket) 4
NOTE:
Tighten the nuts in stage, using a crisscross
pattern.
T R..42 Nm (4.2 m · kg, 30 ft · lb)
FRONT WHEEL AND REAR WHEEL
4. Install:
lCollar 1
NOTE:
Apply the lithium soap base grease on the oil
seal lip.
5. Install:
lWheel
NOTE:
Install the brake disc 1 between the brake
pads 2 correctly.
6. Install:
lDrive chain 1
NOTE:
Push the wheel 2 forward and install the drive
chain.
7. Install:
lChain puller (left) 1
lWheel axle 2
NOTE:
lInstall the chain puller (left), and insert the
wheel axle from left side.
lApply the lithium soap base grease on the
wheel axle.

5 - 10
CHASFRONT BRAKE AND REAR BRAKE
EC5A0000
FRONT BRAKE AND REAR BRAKE
EC5A8000
FRONT BRAKE
Extent of removal:1 Brake hose removal2 Caliper removal
3 Master cylinder removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalFRONT BRAKE REMOVAL
Hold the machine by placing the
suitable stand under the engine.
Drain the brake fluid.
WARNING
Support the machine securely so there is nodanger of it falling over.
Refer to “REMOVAL POINTS”.
1 Hose cover 1
2 Brake hose holder 1
3 Bolt (brake hose holder) 2 Only loosening.
4 Union bolt 2
5 Brake hose 1
6 Pad pin plug 1 Remove when loosening the pad pin.
7 Pad pin 1 Loosen when disassembling the caliper.
8 Caliper 1
9 Brake lever 1
10 Master cylinder bracket 1
11 Master cylinder 1
2
3
1
3
2

5 - 11
CHAS
EC5A8100
REAR BRAKE
Extent of removal:1 Caliper removal2 Brake hose removal
3 Master cylinder removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalREAR BRAKE REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING
Support the machine securely so there is nodanger of it falling over.
Rear wheel Refer to “FRONT WHEEL AND REAR
WHEEL” section.
Drain the brake fluid. Refer to “REMOVAL POINTS”.
1 Pad pin plug 1 Remove when loosening the pad pin.
2 Pad pin 1 Loosen when disassembling the caliper.
3 Caliper 1
4 Brake hose holder 2
5 Union bolt 2
6 Brake hose 1
7 Brake pedal 1
8 Reservoir tank 1
9 Reservoir hose 1
10 Master cylinder 1
3
1
321
FRONT BRAKE AND REAR BRAKE

5 - 12
CHAS
EC5A8200
CALIPER DISASSEMBLY
Front
õRear
Extent of removal:1 Front caliper disassembly2 Rear caliper disassembly
Extent of removal Order Part name Q’ty Remarks
CALIPER DISASSEMBLYAB
1 Pad pin 1 1
2 Brake pad 2 2
3 Pad support 1 1
4 Caliper piston 2 1 Refer to “REMOVAL POINTS”.
5 Dust seal 2 1
Refer to “REMOVAL POINTS”.
6 Piston seal 2 1
12
FRONT BRAKE AND REAR BRAKE

5 - 13
CHASFRONT BRAKE AND REAR BRAKE
EC5A8300
MASTER CYLINDER DISASSEMBLY
Front
õRear
Extent of removal:1 Front master cylinder disassembly2 Rear master cylinder disassembly
Extent of removal Order Part name Q’ty Remarks
MASTER CYLINDER DISAS-
SEMBLY
1 Master cylinder cap 1
2 Diaphragm 1
3 Master cylinder boot 1
4 Circlip 1 Use a long nose circlip pliers.
5 Plain washer 1
6 Push rod 1
7 Master cylinder kit
1
12
21