Removing The Front Brake Master Cylinder; Checking The Front Brake Master Cylinder; Assembling The Front Brake Master Cylinder - Yamaha WR450FB 2012 Owner's Service Manual

• 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.
ECA13540
NOTICE
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 3-20.
5. Check:
• Brake fluid level
Below the minimum level mark
recommended brake fluid to the proper lev-
el.
Refer to "CHECKING THE BRAKE FLUID
LEVEL" on page 3-17.
6. Check:
• Brake lever free play
Refer to "ADJUSTING THE FRONT DISC
BRAKE" on page 3-18.
• Brake lever operation
Soft or spongy feeling
system.
Refer to "BLEEDING THE HYDRAULIC
BRAKE SYSTEM" on page 3-20.
EAS22490
REMOVING THE FRONT BRAKE MASTER
CYLINDER
TIP
Before removing the front brake master cylin-
der, drain the brake fluid from the entire brake
system.
1. Remove:
• Union bolt
• Copper washers
• Brake hose
TIP
To collect any remaining brake fluid, place a
container under the master cylinder and the
end of the brake hose.
Add the
Bleed the brake
5-24
FRONT BRAKE
EAS22500
CHECKING THE FRONT BRAKE MASTER
CYLINDER
1. Check:
• Brake master cylinder "1"
Damage/scratches/wear
• Brake fluid delivery passages "2"
(brake master cylinder body)
Obstruction Blow out with compressed
air.
2. Check:
• Brake master cylinder kit
Damage/scratches/wear
3. Check:
• Brake master cylinder reservoir cap
4. Check:
• Brake master cylinder reservoir diaphragm
holder
• Brake master cylinder reservoir diaphragm
holder
Cracks/damage/wear
5. Check:
• Brake hoses
Cracks/damage/wear
EAS22520
ASSEMBLING THE FRONT BRAKE MAS-
TER CYLINDER
EWA13520
WARNING
• 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.
Recommended fluid
DOT 4
Replace.
1
2
Replace.
Replace.
Replace.