Yamaha Wr250r 2008 Manual

							 
FRONT BRAKE 
4-11 
EAS22210 
FRONT BRAKE 
Removing the front brake pads
Order Job/Parts to remove Q’ty Remarks  
1 Pin plug 1 WR250X only
2 Front brake caliper support bolt 1
3 Front brake caliper assembly 1
4 Brake pad 2
5 Brake pad spring 2
For installation, reverse the removal proce-
dure.
1 2
23
45S
S
WR250X
T R..23 Nm (2.3 m • kg, 17 ft • Ib) 
T R..17 Nm (1.7 m • kg, 12 ft • Ib) 
T R..17 Nm (1.7 m • kg, 12 ft • Ib) 
T R..2.5 Nm (0.25 m • kg, 1.8 ft • Ib)  
						

							 
FRONT BRAKE 
4-12 
Removing the front brake master cylinder
Order Job/Parts to remove Q’ty Remarks  
Brake fluidDrain.
Refer to“BLEEDING THE HYDRAULIC 
BRAKE SYSTEM” on page 1-25.
1 Rear view mirror (right) 1
2 Brake lever 1
3 Front brake switch 1
4 Union bolt 1
5 Copper washer 2
6 Front brake hose 1
7 Brake master cylinder reservoir cap 1
8Brake master cylinder reservoir diaphragm 
holder1
9 Brake master cylinder reservoir diaphragm 1
10 Front brake master cylinder holder 1
11 Front brake master cylinder 1
For installation, reverse the removal proce-
dure.
S
1
2
3
45
6 7
8
910
11
SS
T R..7 Nm (0.7 m • kg, 5.1 ft • Ib) T R..4 Nm (0.4 m • kg, 2.9 ft • Ib) 
T R..7 Nm (0.7 m • kg, 5.1 ft • Ib) 
T R..30 Nm (3.0 m • kg, 22 ft • Ib) 
T R..4 Nm (0.4 m • kg, 2.9 ft • Ib)  
						

							 
FRONT BRAKE 
4-13 
Disassembling the front brake master cylinder
Order Job/Parts to remove Q’ty Remarks  
1 Master cylinder kit 1
For assembly, reverse the disassembly pro-
cedure.
1 
						

							 
FRONT BRAKE 
4-14 
Removing the front brake calipers
Order Job/Parts to remove Q’ty Remarks  
Brake fluidDrain.
Refer to“BLEEDING THE HYDRAULIC 
BRAKE SYSTEM” on page 1-25.
1 Brake hose holder 1
2 Union bolt 1
3 Copper washer 2
4 Front brake hose 1
5 Pin plug 1 Only WR250X
6 Front brake caliper support bolt 1
7 Brake pad 2
8 Brake pad spring 2
9 Front brake caliper assembly 1
10 Front brake caliper bracket 1
For installation, reverse the removal proce-
dure.
S
56
69
78
101
4
S
2
3
T R..2.5 Nm (0.25 m • kg, 1.8 ft • Ib) 
T R..17 Nm (1.7 m • kg, 12 ft • Ib) 
T R..6 Nm (0.6 m • kg, 4.3 ft • Ib) 
T R..23 Nm (2.3 m • kg, 17 ft • Ib) 
T R..10 Nm (1.0 m • kg, 7.2 ft • Ib) 
T R..30 Nm (3.0 m • kg, 22 ft • Ib) 
T R..17 Nm (1.7 m • kg, 12 ft • Ib) 
WR250X 
						

							 
FRONT BRAKE 
4-15 
Disassembling the front brake calipers
Order Job/Parts to remove Q’ty Remarks  
1 Brake caliper piston 2
2 Brake caliper dust seal 2
3 Brake caliper piston seal 2
4 Bleed screw 1
For assembly, reverse the disassembly pro-
cedure.
12
34
S
S
BF
BF
T R..6 Nm (0.6 m • kg, 4.3 ft • Ib)  
						

							 
FRONT BRAKE 
4-16 
EAS22220 
INTRODUCTION
WARNING
 
EWA14100  
Disc brake components rarely require disas-
sembly. Therefore, always follow these pre-
ventive measures: 
 
Never disassemble brake components un-
less absolutely necessary. 
 
If any connection on the hydraulic brake
system is disconnected, the entire brake
system must be disassembled, drained,
cleaned, properly filled, and bled after reas-
sembly. 
 
Never use solvents on internal brake com-
ponents. 
 
Use only clean or new brake fluid for clean-
ing brake components. 
 
Brake fluid may damage painted surfaces
and plastic parts. Therefore, always clean
up any spilt brake fluid immediately. 
 
Avoid brake fluid coming into contact with
the eyes as it can cause serious injury. 
 
FIRST AID FOR BRAKE FLUID ENTERING
THE EYES: 
 
Flush with water for 15 minutes and get im- 
mediate medical attention. 
EAS22230 
CHECKING THE FRONT BRAKE DISC 
1. Remove: 
 
Front wheel
Refer to “FRONT WHEEL” on page 4-2.
2. Check: 
 
Front brake disc
Damage/galling  
→ 
 Replace.
3. Measure: 
 
Brake disc deflection
Out of specification  
→ 
 Correct the brake disc
deflection or replace the brake disc.

 
a. Place the vehicle on a suitable stand so that
the front wheel is elevated.
b. Before measuring the front brake disc deflec-
tion, turn the handlebar to the left or right to
ensure that the front wheel is stationary.
c. Remove the brake caliper.
d. Hold the dial gauge at a right angle against
the brake disc surface.
e. Measure the deflection front 10 mm (0.39 in),
rear 7 mm (0.28 in) below the edge of the
brake disc.

 
4. Measure: 
 
Brake disc thickness
Measure the brake disc thickness at a few dif-
ferent locations.
Out of specification  
→  
 Replace.
5. Adjust: 
 
Brake disc deflection

 
a. Remove the brake disc.
b. Turn the brake disc by one bolt hole.
c. Install the brake disc.
NOTE:
 
Tighten the brake disc bolts in stages and in a 
crisscross pattern. 
Brake disc deflection limit
0.15 mm (0.0059 in) 
Brake disc thickness limit
WR250R 3.0 mm (0.12 in)
WR250X 3.5 mm (0.14 in) 
						

							 
FRONT BRAKE 
4-17 
d. Measure the brake disc deflection.
e. If out of specification, repeat the adjustment
steps until the brake disc deflection is within
specification.
f. If the brake disc deflection cannot be brought
within specification, replace the brake disc.

 
6. Install: 
 
Front wheel
Refer to “FRONT WHEEL” on page 4-2. 
EAS22280 
REPLACING THE FRONT BRAKE PADS
NOTE:
 
When replacing the brake pads, it is not neces-
sary to disconnect the brake hose or disassem- 
ble the brake caliper.
1. Measure: 
 
Brake pad wear limit “a”
Out of specification  
→ 
 Replace the brake
pads as a set.2. Install: 
 
Brake pads 
 
Brake pad spring
NOTE:
 
Always install new brake pads, and a brake pad 
spring as a set.

 
a. Connect a clear plastic hose “1” tightly to the
bleed screw “2”. Put the other end of the hose
into an open container.
b. Loosen the bleed screw and push the brake
caliper pistons into the brake caliper with your
finger.
c. Tighten the bleed screw.
d. Install new brake pads and a new brake pad
spring.

 
3. Install: 
 
Brake pad pins 
 
Brake pad clips 
 
Brake pad cover 
 
Brake caliper 
Brake disc bolt
WR250R:12 Nm (1.2 m•kg, 8.7
ft•lb)
LOCTITE®
WR250X:23 Nm (2.3 m•kg, 17
ft•lb)
LOCTITE®
Brake pad lining thickness (inner)
WR250R 4.8 mm (0.19 in)
WR250X 4.0 mm (0.16 in)
Limit
1.0 mm (0.04 in)
Brake pad lining thickness (outer)
WR250R 4.8 mm (0.19 in)
WR250X 4.0 mm (0.16 in)
Limit
1.0 mm (0.04 in)
LT
TR..
 
Bleed screw
6 Nm (0.6 m•kg, 4.3 ft•lb)
Brake caliper bolt
23 Nm (2.3 m•kg, 17 ft•lb)
a
1
2
TR..
TR.. 
						

							 
FRONT BRAKE 
4-18 
4. Check: 
 
Brake fluid level
Below the minimum level mark “a”  
→ 
 Add the
recommended brake fluid to the proper level.
Refer to “CHECKING THE BRAKE FLUID
LEVEL” on page 1-23.
5. Check: 
 
Brake lever free play
Refer to “ADJUSTING THE FRONT DISC
BRAKE” on page 1-22. 
 
Brake pedal operation
Soft or spongy feeling  
→ 
 Bleed the brake
system.
Refer to “BLEEDING THE HYDRAULIC
BRAKE SYSTEM” on page 1-25. 
EAS22290 
REMOVING THE FRONT BRAKE CALIPER
NOTE:
 
Before disassembling the brake caliper, drain 
the brake fluid from the entire brake system.
1. Remove: 
 
Union bolt 
 
Copper washers 
 
Brake hose
NOTE:
 
Put the end of the brake hose into a container 
and pump out the brake fluid carefully. 
EAS22320 
DISASSEMBLING THE FRONT BRAKE 
CALIPER 
1. Remove: 
 
Brake caliper pistons “1” 
 
Brake caliper dust seals “2” 
 
Brake caliper piston seals “3”

 
a. Blow compressed air into the brake hose joint
opening to force out the pistons from the
brake caliper.
WARNING
 
EWA13550  
 
Cover the brake caliper piston with a rag.
Be careful not to get injured when the pis-
ton is expelled from the brake caliper. 
 
Never try to pry out the brake caliper pis- 
ton. 
b. Remove the dust seals and brake caliper pis-
ton seals.

 
EAS22380 
CHECKING THE FRONT BRAKE CALIPER 
1. Check: 
 
Brake caliper pistons “1”
Rust/scratches/wear  
→  
 Replace the brake
caliper pistons.
a
 
Recommended brake component replacement 
schedule  
Brake pads If necessary
Piston seals Every two years
Brake hoses Every four years
Brake fluidEvery two years and 
whenever the brake is dis-
assembled
3
2
1 
						

							 
FRONT BRAKE 
4-19 
 
Brake caliper cylinders “2”
Scratches/wear  
→ 
 Replace the brake caliper
assembly. 
 
Brake caliper body “3”
Cracks/damage  
→ 
 Replace the brake caliper
assembly. 
 
Brake fluid delivery passages
(brake caliper body)
Obstruction  
→ 
 Blow out with compressed air.
WARNING
 
EWA13600  
Whenever a brake caliper is disassembled, 
replace the piston seals. 
2. Check: 
 
Brake caliper bracket
Cracks/damage  
→ 
 Replace. 
EAS22400 
ASSEMBLING THE FRONT BRAKE CALIPER
WARNING
 
EWA13620  
 
Before installation, all internal brake com-
ponents should be cleaned and lubricated
with clean or new brake fluid. 
 
Never use solvents on internal brake com-
ponents as they will cause the piston seals
to swell and distort. 
 
Whenever a brake caliper is disassembled, 
replace the brake caliper piston seals. 
EAS22420 
INSTALLING THE FRONT BRAKE CALIPER 
1. Install: 
 
Front brake caliper bracket 
 
Front brake caliper
(temporarily) 
 
Copper washers  
 
Brake hose 
 
Union bolt
WARNING
 
EWA13530  
Proper brake hose routing is essential to in-
sure safe vehicle operation. Refer to “CA- 
BLE ROUTING” on page 2-30.
CAUTION:
 
 ECA14170 
When installing the brake hose onto the
brake caliper “1”, make sure the brake pipe
“a” touches the projection “b” on the brake 
caliper. 
2. Install: 
 
Front brake caliper 
 
Brake pad springs 
 
Front brake caliper support bolt 
 
Brake hose holder
Refer to “REPLACING THE FRONT BRAKE
PADS” on page 4-17.
3. Fill: 
 
Brake master cylinder reservoir
(with the specified amount of the recom-
mended brake fluid)
WARNING
 
EWA13090  
 
Use only the designated brake fluid. Other
brake fluids may cause the rubber seals to
deteriorate, causing leakage and poor Recommended fluid
DOT 4
2
113
New
 
Front brake caliper bracket
23 Nm (2.3 m•kg, 17 ft•lb)
Brake hose union bolt
30 Nm (30. m•kg, 22 ft•lb)
Front brake caliper support bolt
17 Nm (1.7 m•kg, 12 ft•lb)
Brake hose holder
10 Nm (1.0 m•kg, 7.2 ft•lb)
Recommended fluid
DOT 4
TR..
1b
a
TR.. 
						

							 
FRONT BRAKE 
4-20 
brake performance. 
 
Refill with the same type of brake fluid that
is already in the system. Mixing brake flu-
ids may result in a harmful chemical reac-
tion, leading to poor brake performance. 
 
When refilling, be careful that water does
not enter the brake fluid reservoir. Water
will significantly lower the boiling point of 
the brake fluid and could cause vapor lock.
CAUTION:
 
 ECA13540 
Brake fluid may damage painted surfaces
and plastic parts. Therefore, always clean up 
any spilt brake fluid immediately. 
4. Bleed: 
 
Brake system
Refer to “BLEEDING THE HYDRAULIC
BRAKE SYSTEM” on page 1-25.
5. Check: 
 
Brake fluid level
Below the minimum level mark  
→ 
 Add the
recommended brake fluid to the proper level.
Refer to “CHECKING THE BRAKE FLUID
LEVEL” on page 1-23.
6. Check: 
 
Brake lever free play
Refer to “ADJUSTING THE FRONT DISC
BRAKE” on page 1-22. 
 
Brake lever operation
Soft or spongy feeling  
→ 
 Bleed the brake
system.
Refer to “BLEEDING THE HYDRAULIC
BRAKE SYSTEM” on page 1-25. 
EAS22490 
REMOVING THE FRONT BRAKE MASTER 
CYLINDER
NOTE:
 
Before removing the front brake master cylinder,
drain the brake fluid from the entire brake sys- 
tem.
1. Disconnect: 
 
Brake switch coupler “1”
(from the brake master cylinder)2. Remove: 
 
Union bolt 
 
Copper washers 
 
Brake hoses
NOTE:
 
To collect any remaining brake fluid, place a
container under the master cylinder and the end 
of the brake hose. 
EAS22500 
CHECKING THE FRONT BRAKE MASTER 
CYLINDER 
1. Check: 
 
Brake master cylinder “1”
Damage/scratches/wear  
→  
 Replace. 
 
Brake fluid delivery passages “2”
(brake master cylinder body)
Obstruction  
→  
 Blow out with compressed air.
2. Check: 
 
Brake master cylinder kit
Damage/scratches/wear  
→  
 Replace.
3. Check: 
 
Brake master cylinder reservoir cap
4. Check: 
 
Brake master cylinder reservoir diaphragm
holder 
 
Brake master cylinder reservoir diaphragm
holder
Cracks/damage  
→  
 Replace.
5. Check: 
 
Brake hoses
Cracks/damage/wear  
→  
 Replace.
1
2