2009 YAMAHA WR 250F brake

6-4
FRONT WHEEL AND REAR WHEEL
2. Install:•Brake disc "1"
• Bolt (brake disc) "2"
Tighten the bolts in stage, using a
crisscross pattern.
3. Install:•Collar "1"
Apply the lithium soap base grease
on the oil seal lip.
4. Install:• Speed sensor "1"
• Apply the lithium soap base grease
on the oil seal lip of the speed sen-
sor.
• Make sure the two projections "a" in
the wheel hub are meshed with the
two slots "b" in the speed sensor.
5. Install:• Wheel
• Install the brake disc "1" between the brake pads "2" correctly.
• Make sure that the projections "a" in
the speed sensor fits over the stop-
per "b" on the front fork inner tube.
6. Install:• Wheel axle "1"
Apply the lithium soap base grease
on the wheel axle.
7. Install:• Nut (wheel axle) "1"
8. Tighten: • Bolt (axle holder) "1"
Before tightening the bolt, fit the
wheel axle to the axle holder by strok-
ing the front fork several times with
the front brake applied.
INSTALLING THE REAR WHEEL
1. Install:• Bearing (right) "1"
• Circlip "2"
•Spacer "3"
• Bearing (left) "4"
•Oil seal "5"
• 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 out- side diameter of the race of the
bearing.
• Right side of bearing shall be in- stalled first.
• Install the oil seal with its manufac- ture's marks or numbers facing out-
ward.
Do not strike the inner race of the
bearing. Contact should be made
only with the outer race.
Bolt (brake disc): 12 Nm (1.2 m•kg, 8.7
ft•lb)
Nut (wheel axle):
90 Nm (9.0 m•kg, 65
ft•lb)
Bolt (axle holder): 21 Nm (2.1 m•kg, 15
ft•lb)

6-5
FRONT WHEEL AND REAR WHEEL
2. Install:•Brake disc "1"
• Bolt (brake disc) "2"
Tighten the bolts in stage, using a
crisscross pattern.
3. Install:• Rear wheel sprocket "1"
• Bolt (rear wheel sprocket) "2"
• Washer (rear wheel sprocket) "3"
• Nut (rear wheel sprocket) "4"
Tighten the nuts in stage, using a
crisscross pattern.
4. Install:•Collar "1"
Apply the lithium soap base grease
on the oil seal lip.
5. Install:
• Wheel
Install the brake disc "1" between the
brake pads "2" correctly.
6. Install:• Drive chain "1"
Push the wheel "2" forward and install
the drive chain.
7. Install:• Left drive chain puller "1"
• Wheel axle "2"
• Install the left drive chain puller, and
insert the wheel axle from left side.
• Apply the lithium soap base grease
on the wheel axle.
8. Install:• Right drive chain puller "1"
•Washer "2"
• Nut (wheel axle) "3"
Temporarily tighten the nut (wheel
axle) at this point.
9. Adjust:
• Drive chain slack "a"
Refer to "ADJUSTING THE
DRIVE CHAIN SLACK" section in
the CHAPTER 3.
10. Tighten: • Nut (wheel axle) "1"
•Locknut "2"
Bolt (brake disc):
14 Nm (1.4 m•kg, 10
ft•lb)
Nut (rear wheel sprock-
et): 50 Nm (5.0 m•kg, 36
ft•lb)
Drive chain slack:
48–58 mm (1.9–2.3 in)
Nut (wheel axle): 125 Nm (12.5 m•kg, 90
ft•lb)
Locknut: 19 Nm (1.9 m•kg, 13
ft•lb)

6-6
FRONT BRAKE AND REAR BRAKE
FRONT BRAKE AND REAR BRAKE
REMOVING THE FRONT BRAKEOrder Part name Q'ty Remarks Hold the machine by placing the suitable stand
under the engine. Refer to "HANDLING NOTE".
Drain the brake fluid. Refer to removal section.
1 Brake hose holder (protector) 2
2 Brake hose holder (brake caliper) 1
3 Union bolt 2
4Brake hose 1
5 Pad pin plug 1 Remove when loosening the pad pin.
6 Pad pin 1Loosen when disassembling the brake cali-
per.
7 Brake caliper 1
8Brake lever 1
9 Brake master cylinder bracket 1
10 Brake master cylinder 1

6-7
FRONT BRAKE AND REAR BRAKE
REMOVING THE REAR BRAKEOrder 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
5Brake hose 1
6 Pad pin plug 1 Remove when loosening the pad pin.
7 Pad pin 1Loosen when disassembling the brake cali-
per.
8 Brake caliper 1

6-8
FRONT BRAKE AND REAR BRAKE
DISASSEMBLING THE BRAKE CALIPEROrder Part name Q'ty Remarks A. Front
B. Rear
AB
1 Pad pin 1 1
2Brake pad 22
3 Pad support 1 1
4 Brake caliper piston 2 1 Refer to removal section.
5 Brake caliper piston dust seal 2 1 Refer to removal section.
6 Brake caliper piston seal 2 1 Refer to removal section.

6-9
FRONT BRAKE AND REAR BRAKE
DISASSEMBLING THE BRAKE MASTER CYLINDEROrder Part name Q'ty Remarks A. Front
B. Rear
1 Brake master cylinder cap 1
2 Diaphragm 1
3 Reservoir float 1
4 Brake master cylinder boot 1
5 Circlip 1 Use a long nose circlip pliers.
6 Washer 1
7 Push rod 1
8 Brake master cylinder kit 1

6-10
FRONT BRAKE AND REAR BRAKE
HANDLING NOTE
Support the machine securely so
there is no danger of it falling over.
DRAINING THE BRAKE FLUID
1. Remove:• Brake master cylinder cap "1"
• Protector (rear brake)
Do not remove the diaphragm.
A. Front
B. Rear
2. Connect the transparent hose "2" to the bleed screw "1" and place a
suitable container under its end.
A. Front
B. Rear
3. Loosen the bleed screw and drain the brake fluid while pulling the le-
ver in or pushing down on the
pedal.
• Do not reuse the drained brake
fluid.
• Brake fluid may erode painted
surfaces or plastic parts. Always
clean up spilled fluid immediate-
ly.
REMOVING THE BRAKE CALIPER
PISTON
1. Remove:• Brake caliper piston
Use compressed air and proceed
carefully.
• Cover piston with rag and use ex-treme caution when expelling
piston from cylinder.
• Never attempt to pry out piston.
Caliper piston removal steps:
a. Insert a piece of rag into the brake caliper to lock one brake caliper.
b. Carefully force the piston out of the brake caliper cylinder with
compressed air.
A. Front
B. Rear
REMOVING THE BRAKE CALIPER
PISTON SEAL KIT
1. Remove:• Brake caliper piston dust seal "1"
• Brake caliper piston seal "2"
Remove the brake caliper piston
seals and brake caliper piston dust
seals by pushing them with a finger.
Never attempt to pry out brake cal-
iper piston seals and brake caliper
piston dust seals.
Replace the brake caliper piston
seals and brake caliper piston dust
seals whenever a caliper is disas-
sembled.
A. Front
B. Rear
CHECKING THE BRAKE MASTER
CYLINDER
1. Inspect: • Brake master cylinder inner sur-face "a"
Wear/scratches → Replace mas-
ter cylinder assembly.
Stains →Clean.
Use only new brake fluid.
A. Front
B. Rear
2. Inspect: • Diaphragm "1"Crack/damage →Replace.
A. Front
B. Rear

6-11
FRONT BRAKE AND REAR BRAKE
3. Inspect: (front brake only)• Reservoir float "1"Damage →Replace.
4. Inspect: • Brake master cylinder piston "1"
• Brake master cylinder cup "2"Wear/damage/score marks →Re-
place brake master cylinder kit.
A. Front
B. Rear
CHECKING THE BRAKE CALIPER
1. Inspect: • Brake caliper cylinder inner sur-face "a"
Wear/score marks →Replace
brake caliper assembly.
A. Front
B. Rear
2. Inspect: • Brake caliper piston "1"
Wear/score marks →Replace
brake caliper piston assembly.
Replace the brake caliper piston
seals and brake caliper piston dust
seals "2" whenever a caliper is dis-
assembled.
CHECKING THE BRAKE HOSE
1. Inspect: • Brake hose "1"Crack/damage →Replace.
HANDLING NOTE
• All internal parts should be cleaned in new brake fluid only.
• Internal parts should be lubricat-
ed with brake fluid when in-
stalled.
• Replace the brake caliper piston
seals and brake caliper piston
dust seals whenever a caliper is
disassembled.
INSTALLING THE BRAKE
CALIPER PISTON
1. Clean:• Brake caliper
• Brake caliper piston seal
• Brake caliper piston dust seal
• Brake caliper pistonClean them with brake fluid.
2. Install:
• Brake caliper piston seal "1"
• Brake caliper piston dust seal "2"
Always use new brake caliper pis-
ton seals and brake caliper piston
dust seals.
• Apply the brake fluid on the brake caliper piston seal.
• Apply the silicone grease on the brake caliper piston dust seal.
• Fit the brake caliper piston seals and brake caliper piston dust seals
onto the slot on brake caliper cor-
rectly.
A. Front
B. Rear
3. Install:
• Brake caliper piston "1"
Apply the brake fluid on the piston
wall.
• Install the piston with its shallow depressed side "a" facing the
brake caliper.
• Never force to insert.
A. Front
B. Rear