Yamaha WR250F 2022 User Manual

REAR BRAKE
4-34
cleaning and lubricating.
• Never use solvents on internal brake com-
ponents as they will cause the piston seals
to swell and distort.
• When the brake caliper is disassembled, re-
place the brake caliper piston seal and the
brake caliper piston dust seal with new
ones.
EAM30047
INSTALLING THE REAR BRAKE CALIPER
1. Install:
• Rear brake caliper
• Rear brake caliper bracket
2. Install:
• Rear wheel
Refer to “REAR WHEEL” on page 4-12.
• Copper washer
• Brake hose
• Union bolt
WARNING
EWA13531
Proper brake hose routing is essential to in-
sure safe vehicle operation.
NOTICE
ECA24490
Make sure that a bend in its pipe portion “a”
is directed as shown and the brake hose
touches the projection “b” on the brake cali-
per.
3. Install:
• Brake pad spring
• Brake pad
• Brake pad pin
• Brake pad pin plug
Refer to “CHECKING THE REAR BRAKE
PADS” on page 3-24.
4. Pour brake fluid to the brake fluid reservoir up
to the specified level.
WARNING
EWA13090
• Use only the designated brake fluid. Other
brake fluids may cause the rubber seals to
deteriorate, causing leakage and poor
brake performance.
• Refill with the same type of brake fluid that
is already in the system. Mixing brake fluids
may result in a harmful chemical reaction,
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.
NOTICE
ECA13540
Brake fluid may damage painted surfaces
and plastic parts. Therefore, always clean up
any spilt brake fluid immediately.
5. Bleed:
• Brake system
Refer to “BLEEDING THE HYDRAULIC
BRAKE SYSTEM” on page 3-25.
6. Check:
• Brake fluid level
The minimum level mark or below  Add.
Refer to “CHECKING THE BRAKE FLUID
LEVEL” on page 3-23.
7. Check:
• Brake pedal operation
A softy or spongy feeling  Bleed the brake
system.
Refer to “BLEEDING THE HYDRAULIC
BRAKE SYSTEM” on page 3-25.
EAM30048
REMOVING THE REAR BRAKE MASTER
CYLINDER
TIP
Before removing the rear brake master cylinder,
drain the brake fluid from the entire brake sys-
Specified brake fluid
DOT 4
Brake hose union bolt
30 N·m (3.0 kgf·m, 22 lb·ft)
New
T
R
.
.
b
b
a
Brake pad pin
17 N·m (1.7 kgf·m, 13 lb·ft)
Brake pad pin plug
2.5 N·m (0.25 kgf·m, 1.8 lb·ft)
Specified brake fluid
DOT 4
T
R
.
.

Yamaha WR250F 2022 Specifications

General

Bore x Stroke	77.0mm x 53.6mm
Compression Ratio	13.8:1
Ignition	TCI: Transistor Controlled Ignition
Final Drive	Chain
Suspension Rear	KYB® single shock; fully adjustable, 12.5-in travel
Length	85.6 in
Width	32.5 in
Height	50.0 in
Seat Height	38.2 in
Wheelbase	58.3 in
Rake (Caster Angle)	27.2°
Trail	4.6 in
Fuel Capacity	2.2 gal
Wet Weight	254 lb
Engine Type	Liquid-cooled, DOHC, 4-stroke
Fuel Delivery	Fuel injection
Suspension Front	KYB® Speed-Sensitive System inverted fork; fully adjustable
Brakes Front	Hydraulic single disc
Brakes Rear	Hydraulic single disc brake
Tires Front	80/100-21
Tires Rear	110/100-18