Removing The Front Brake Master Cylinder; Checking The Front Brake Master Cylinder; Assembling The Front Brake Master Cylinder - Yamaha YZ 2020 Series Owner's Service Manual

stalled with its upper end "a" aligned with the
paint "b" on the brake hose.
2
b
a
4. Pour brake fluid to the brake master cylinder
reservoir up to the specified level.
Specified brake fluid
DOT 4
EWA13090
WARNING
• 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.
ECA13540
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 HYDRAULIC
BRAKE SYSTEM" on page 3-24.
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 lever free play
Refer to "ADJUSTING THE FRONT DISC
BRAKE" on page 3-22.
• Brake lever operation
A softy or spongy feeling  Bleed the brake
system.
Refer to "BLEEDING THE HYDRAULIC
BRAKE SYSTEM" on page 3-24.
EAM30036
REMOVING THE FRONT BRAKE MASTER
CYLINDER
TIP
Before removing the front brake master cylinder,
drain the brake fluid from the entire brake sys-
tem.
1. Remove:
1
• Union bolt
• Copper washer
• Brake hose
TIP
To drain any remaining brake fluid, place a con-
tainer under the master cylinder and the end of
the brake hose.
EAM30037
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 hose
Cracks/damage/wear  Replace.
EAM30038
ASSEMBLING THE FRONT BRAKE MASTER
CYLINDER
EWA13520
WARNING
• Before installation, all internal brake com-
4-21
FRONT BRAKE
1
2