Yamaha WR250F(Y) 2009, Owner'S Service Manual

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3-22
CHASSIS
i. Install the brake caliper "12" and
rear wheel "13".
Refer to "FRONT WHEEL AND
REAR WHEEL" section in the
CHAPTER 6.
j. Tighten the pad pin "14".
k. Install the pad pin plug "15" and
protector "16".
3. Inspect:
• Brake fluid level
Refer to "CHECKING THE
BRAKE FLUID LEVEL" section.
4. Check:
• Brake pedal operation
A softy or spongy feeling
→
Bleed
brake system.
Refer to "BLEEDING THE HY-
DRAULIC BRAKE SYSTEM" sec-
tion.
CHECKING THE REAR BRAKE
PAD INSULATOR
1. Remove:
• Brake pad
Refer to "CHECKING AND RE-
PLACING THE REAR BRAKE
PADS" section.
2. Inspect:
• Rear brake pad insulator "1"
Damage
→
Replace.
CHECKING THE BRAKE FLUID
LEVEL
1. Place the brake master cylinder
so that its top is in a horizontal po-
sition.
2. Inspect:
• Brake fluid level
Fluid at lower level
→
Fill up.
• Use only designated quality
brake fluid to avoid poor brake
performance.
• Refill with same type and brand
of brake fluid; mixing fluids
could result in poor brake perfor-
mance.
• Be sure that water or other con-
taminants do not enter master
cylinder when refilling.
• Clean up spilled fluid immediate-
ly to avoid erosion of painted
surfaces or plastic parts.
a. Lower level
A. Front
B. Rear
CHECKING THE SPROCKET
1. Inspect:
• Sprocket teeth "a"
Excessive wear
→
Replace.
Replace the drive sprocket, rear
wheel sprocket and drive chain as a
set.
CHECKING THE DRIVE CHAIN
1. Measure:
• Drive chain length (15 links) "a"
Out of specification
→
Replace.
• While measuring the drive chain
length, push down on the drive
chain to increase its tension.
• Measure the length between drive
chain roller "1" and "16" as shown.
• Perform this measurement at two or
three different places.
2. Remove:
• Drive chain "1"
Remove the drive chain using a drive
chain cutter "2".
3. Clean:
• Drive chain
Brush off as much dirt as possi-
ble. Then clean the drive chain
using the chain cleaner.
This machine has a drive chain
with small rubber O-rings "1" be-
tween the side plates. Steam
cleaning, high-pressure washes,
certain solvent and kerosene can
damage these O-rings.
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 (protector):
7 Nm (0.7 m•kg, 5.1
ft•lb)
Recommended brake flu-
id:
DOT #4
Drive chain length (15
links):
<Limit>: 239.3 mm
(9.42 in)