brake YAMAHA YZ450F 2007 Owner's Guide

5 - 4
CHASFRONT WHEEL AND REAR WHEEL
EC514200
Wheel axle
1. Measure:
Wheel 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:
Brake 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:
Brake disc thickness a
Out of limit → Replace.
Disc deflection limit:
Standard
Rear—0.15 mm
(0.006 in)
Disc wear limit:
Standard
Front3.0 mm (0.12 in) 2.5 mm (0.10 in)
Rear4.0 mm (0.16 in) 3.5 mm (0.14 in)

5 - 5
CHASFRONT WHEEL AND REAR WHEEL
EC595000
ASSEMBLY AND INSTALLATION
Front wheel
1. Install:
Bearing (left) 1
Spacer 2
Bearing (right) 3
Oil seal 4
NOTE:
Apply the lithium soap base grease on the
bearing and oil seal lip when installing.
Use a socket that matches the outside diam-
eter of the race of the bearing.
Left 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.
2. Install:
Brake disc 1
Bolt (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:
Collar 1
NOTE:
Apply the lithium soap base grease on the oil
seal lip.
Install the collars with their projections a
facing the wheel.
4. Install:
Wheel
NOTE:
Install the brake disc 1 between the brake
pads 2 correctly.

5 - 6
CHASFRONT WHEEL AND REAR WHEEL
5. Install:
Wheel axle 1
NOTE:
Apply the lithium soap base grease on the
wheel axle.
6. Install:
Nut (wheel axle) 1
T R..105 Nm (10.5 m · kg, 75 ft · lb)
7. Tighten:
Bolt (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.
T R..21 Nm (2.1 m · kg, 15 ft · lb)

5 - 7
CHASFRONT WHEEL AND REAR WHEEL
Rear wheel
1. Install:
Bearing (right) 1
Circlip 2
Spacer 3
Bearing (left) 4
Oil seal 5
NOTE:
Apply the lithium soap base grease on the
bearing and 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
New
2. Install:
Brake disc 1
Bolt (brake disc) 2
NOTE:
Tighten the bolts in stage, using a crisscross
pattern.
3. Install:
Driven sprocket 1
Bolt (driven sprocket) 2
Plain washer (driven sprocket) 3
Nut (driven sprocket) 4
NOTE:
Tighten the nuts in stage, using a crisscross
pattern.
T R..14 Nm (1.4 m · kg, 10 ft · lb)
T R..42 Nm (4.2 m · kg, 30 ft · lb)

5 - 8
CHAS
4. Install:
Collar 1
NOTE:
Apply the lithium soap base grease on the oil
seal lip.
5. Install:
Wheel
NOTE:
Install the brake disc 1 between the brake
pads 2 correctly.
6. Install:
Drive chain 1
NOTE:
Push the wheel 2 forward and install the drive
chain.
7. Install:
Chain puller (left) 1
Wheel axle 2
NOTE:
Install the chain puller (left), and insert the
wheel axle from left side.
Apply the lithium soap base grease on the
wheel axle.
8. Install:
Chain puller (right) 1
Plain washer 2
Nut (wheel axle) 3
NOTE:
Temporarily tighten the nut (wheel axle) at this
point.
FRONT WHEEL AND REAR WHEEL

5 - 10
CHASFRONT BRAKE AND REAR BRAKE
EC5A0000
FRONT BRAKE AND REAR BRAKE
EC5A8000
FRONT BRAKE
Extent of removal:
1 Brake hose removal
2 Caliper removal
3 Master cylinder removal
Extent of removal Order Part name Q’ty Remarks
FRONT BRAKE REMOVAL
WARNING
Support the machine securely so there is no
danger of it falling over.
Preparation for removal Hold the machine by placing the
suitable stand under the engine.
Drain the brake fluid. Refer to “REMOVAL POINTS”.
1 Brake hose holder (protector) 2
2 Brake hose holder (caliper) 1
3 Union bolt 2
4 Brake hose 1
5 Pad pin plug 1 Remove when loosening the pad pin.
6 Pad pin 1 Loosen when disassembling the caliper.
7 Caliper 1
8Brake lever 1
9 Master cylinder bracket 1
10 Master cylinder 1
2
3
132

5 - 11
CHAS
EC5A8100
REAR BRAKE
Extent of removal:
1 Master cylinder removal
2 Brake hose removal
3 Caliper removal
Extent of removal Order Part name Q’ty Remarks
REAR BRAKE REMOVAL
WARNING
Support the machine securely so there is no
danger of it falling over.
Preparation for removal Hold the machine by placing the
suitable stand under the engine.
Rear wheel Refer to “FRONT WHEEL AND REAR
WHEEL” section.
Drain the brake fluid. Refer to “REMOVAL POINTS”.
1 Brake pedal 1
2 Master cylinder 1
3 Brake hose holder 2
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
3
1
321
FRONT BRAKE AND REAR BRAKE

5 - 12
CHAS
EC5A8200
CALIPER DISASSEMBLY
ÈFront
ÉRear
Extent of removal:
1 Front caliper disassembly
2 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
6 Piston seal 2 1
12
FRONT BRAKE AND REAR BRAKE

5 - 13
CHASFRONT BRAKE AND REAR BRAKE
EC5A8300
MASTER CYLINDER DISASSEMBLY
ÈFront
ÉRear
Extent of removal:
1 Front master cylinder disassembly
2 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 Reservoir float 1
4 Master cylinder boot 1
5 Circlip 1 Use a long nose circlip pliers.
6 Plain washer 1
7 Push rod 1
8 Master cylinder kit 1
1
2
12
2

5 - 14
CHASFRONT BRAKE AND REAR BRAKE
EC5A3000
REMOVAL POINTS
Brake fluid
1. Remove:
[Front]
Master cylinder cap 1
[Rear]
Master cylinder cap 1
Protector
NOTE:
Do not remove the diaphragm.
ÈFront
ÉRear
2. Connect the transparent hose 2 to the
bleed screw 1 and place a suitable con-
tainer under its end.
ÈFront
ÉRear
È
É
3. Loosen the bleed screw and drain the
brake fluid while pulling the lever in or
pushing down on the pedal.
CAUTION:
Do not reuse the drained brake fluid.
Brake fluid may erode painted surfaces or
plastic parts. Always clean up spilled
fluid immediately.
EC533301
Caliper piston
1. Remove:
Caliper piston
Use compressed air and proceed care-
fully.
WARNING
Cover piston with rag and use extreme
caution when expelling piston from cylin-
der.
Never attempt to pry out piston.
ÈFront
ÉRear
Caliper piston removal steps:
Insert a piece of rag into the caliper to lock
one caliper.
Carefully force the piston out of the caliper
cylinder with compressed air.
ÈÉ
È
É