Removing The Front Brake Master Cylinder; Checking The Front Brake Master Cylinder; Assembling The Front Brake Master Cylinder - Yamaha YZ 2018 Series Owner's Service Manual

ECA
NOTICE
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 BRAKE
SYSTEM" on page 3-22.
6. Check:
• Brake fluid level
The minimum level mark or below  Add.
Refer to "CHECKING THE BRAKE FLUID
LEVEL" on page 3-27.
7. Check:
• Brake lever free play
Refer to "ADJUSTING THE FRONT
BRAKE" on page 3-23.
• Brake lever operation
A softy or spongy feeling  Bleed the brake
system.
Refer to "BLEEDING THE BRAKE
SYSTEM" on page 3-22.
EASB29B149
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 hoses
TIP
To drain any remaining brake fluid, place a con-
tainer under the master cylinder and the end of
the brake hose.
EASB29B150
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 hoses
Cracks/damage/wear  Replace.
EASB29B151
ASSEMBLING THE FRONT BRAKE MAS-
TER CYLINDER
EWA
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.
Specified brake fluid
DOT 4
1. Wash the brake master cylinder and the
brake master cylinder kit with brake fluid.
2. Install:
• Primary cylinder cup "1"
• Secondary cylinder cup "2"
Install to the brake master cylinder piston
"3".
EWA
WARNING
Apply brake fluid to the cylinder cups and
install them as shown. Wrong orientation in
installation causes poor braking perfor-
mance.
4-18
FRONT BRAKE
1
2