wheel YAMAHA WR 450F 2008 Owner's Guide

6-7
FRONT BRAKE AND REAR BRAKE
REMOVING THE REAR BRAKE
Order Part name Q'ty Remarks
Hold the machine by placing the suitable stand
under the engine.Refer to "HANDLING NOTE".
Rear wheel Refer to "FRONT WHEEL AND REAR
WHEEL" section.
Drain the brake fluid. Refer to removal section.
1 Brake pedal 1
2 Brake 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.
7Pad pin 1Loosen when disassembling the brake cali-
per.
8 Brake caliper 1

6-12
FRONT BRAKE AND REAR BRAKE
4. Install:
• Pad pin plug "4"
INSTALLING THE REAR BRAKE
CALIPER
1. Install:
• Pad support "1"
• Brake pad "2"
• Pad pin "3"
• Install the brake pads with their pro-
jections "a" into the brake caliper re-
cesses "b".
• Temporarily tighten the pad pin at
this point.
2. Install:
• Brake disc cover "1"
• Bolt (brake disc cover) "2"
3. Install:
• Brake caliper "1"
• Rear wheel "2"
Refer to "FRONT WHEEL AND
REAR WHEEL" section.
4. Tighten:
• Pad pin "3"5. Install:
• Pad pin plug "4"
INSTALLING THE BRAKE
MASTER CYLINDER KIT
1. Clean:
• Brake master cylinder
• Brake master cylinder kit
Clean them with brake fluid.
2. Install:
• Brake master cylinder cup (prima-
ry) "1"
• Brake master cylinder cup (sec-
ondary) "2"
To brake master cylinder piston
"3".
Apply the brake fluid on the brake
master cylinder cup.
After installing, cylinder cup
should be installed as shown di-
rection. Wrong installation cause
improper brake performance.
A. Front
B. Rear
3. Install:
• Spring "1"
To brake master cylinder piston
"2".
Install the spring at the smaller dia.
side.
A. Front
B. Rear
4. Install:
• Brake master cylinder kit "1"
• Washer (front brake) "2"
• Push rod (rear brake) "2"
• Circlip "3"
• Brake master cylinder boot "4"
To brake master cylinder.
• Apply the brake fluid on the brake
master cylinder kit.
• Apply the silicone grease on the tip
of the push rod.
• When installing the circlip, use a
long nose circlip pliers.
A. Front
B. Rear
INSTALLING THE FRONT BRAKE
MASTER CYLINDER
1. Install:
• Brake master cylinder "1"
• Brake master cylinder bracket "2"
• Bolt (brake master cylinder brack-
et) "3"
• Install the bracket so that the arrow
mark "a" face upward.
• First tighten the bolts on the upper
side of the brake master cylinder
bracket, and then tighten the bolts
on the lower side.
Pad pin plug:
3 Nm (0.3 m•kg, 2.2
ft•lb)
Bolt (brake disc cover):
10 Nm (1.0 m•kg, 7.2
ft•lb)
Pad pin:
18 Nm (1.8 m•kg, 13
ft•lb)Pad pin plug:
3 Nm (0.3 m•kg, 2.2
ft•lb)
Bolt (brake master cylin-
der bracket):
9 Nm (0.9 m•kg, 6.5
ft•lb)

6-16
FRONT FORK
FRONT FORK
REMOVING THE FRONT FORK
Order Part name Q'ty Remarks
Hold the machine by placing the suitable stand
under the engine.Refer to "HANDLING NOTE".
Front wheel Refer to "FRONT WHEEL AND REAR
WHEEL" section.
Front brake caliper Refer to "FRONT BRAKE AND REAR
BRAKE" section.
Headlight
Handlebar Refer to "HANDLEBAR" section.
1 Protector 1
2 Pinch bolt (upper bracket) 2 Only loosening.
3 Cap bolt 1 Loosen when disassembling the front fork.
4 Pinch bolt (lower bracket) 2 Only loosening.
5 Front fork 1

7-21
SIGNALING SYSTEM
CHECKING THE COUPLERS AND
LEADS CONNECTION
1. Check:
• Couplers and leads connection
Rust/dust/looseness/short-circuit
→Repair or replace.
CHECKING THE MULTI-FUNCTION
DISPLAY INPUT VOLTAGE
1. Disconnect the multi-function dis-
play coupler.
2. Set the main switch to "ON".
3. Measure:
• Multi-function display input volt-
age
Out of specification→Replace
wire harness.
Make sure that a short-circuit does
not develop between the terminals
because it may cause damage to
electrical components.
CHECKING THE MULTI-FUNCTION
DISPLAY OUTPUT VOLTAGE
1. Disconnect the multi-function dis-
play coupler.
2. Set the main switch to "ON".
3. Measure:
• Multi-function display output volt-
age
Out of specification→Replace
multi-function display.
Make sure that a short-circuit does
not develop between the terminals
because it may cause damage to
electrical components.
CHECKING THE SPEED SENSOR
OUTPUT VOLTAGE
1. Insert the thin electric conductors
"1" (lead) into the speed sensor
coupler "2", as shown, and con-
nect the tester to them.
• Do not insert the electric conduc-
tors more than required because
it may reduce the waterproof
function of the coupler.
• Make sure that a short-circuit
does not develop between the
terminals because it may cause
damage to electrical compo-
nents.
2. Set the main switch to "ON".
3. Measure:
• Speed sensor output voltage
Output voltage not correct→Re-
place the speed sensor.
Measurement steps:
a. Elevate the front wheel and slowly
rotate it.
b. Measure the voltage (DCV) of
white lead and black lead. With
each full rotation of the front
wheel, the voltage reading should
cycle from 0.6 V to 4.8 V to 0.6 V
to 4.8 V.
Tester (+) lead→Brown lead "1"
Tester (-) lead→Black lead "2"
Multi-func-
tion dis-
play input
voltageTester se-
lector posi-
tion
10 V or
moreDCV-20
Tester (+) lead→Red lead "1"
Tester (-) lead→Black/White lead
"2"
Multi-func-
tion dis-
play output
voltageTester se-
lector posi-
tion
4.5 V or
moreDCV-20
Tester (+) lead→White lead "3"
Tester (-) lead→Black lead "4"