FRONT BRAKE
4-19
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 3-15.
6. Check:
•
Brake fluid level
The minimum level mark or below
Add.
Refer to “CHECKING THE BRAKE FLUID
LEVEL” on page 3-14.
7. Check:
•
Brake lever operation
A softy or spongy feeling
Bleed the brake
system.
Refer to “BLEEDING THE HYDRAULIC
BRAKE SYSTEM” on page 3-15.
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:
•
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
WARNING
EWA13520
• 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.
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”
(to the brake master cylinder piston “3”)
WARNING
EWA20240
Apply brake fluid to the cylinder cups and in-
Specified brake fluid
DOT 4
Specified brake fluid
DOT 4
1
2
Summary of Contents for YZ125X 2021
Page 5: ...EAM20162 YAMAHA MOTOR CORPORATION U S A YZ MOTORCYCLE LIMITED WARRANTY ...
Page 8: ......
Page 10: ......
Page 38: ...MOTORCYCLE CARE AND STORAGE 1 26 ...
Page 54: ...CABLE ROUTING DIAGRAM 2 15 EAM20152 CABLE ROUTING DIAGRAM Frame and engine left side view ...
Page 56: ...CABLE ROUTING DIAGRAM 2 17 Frame and engine right side view ...
Page 58: ...CABLE ROUTING DIAGRAM 2 19 Handlebar front view 0 in 0 mm 0 mm 0 in ...
Page 60: ...CABLE ROUTING DIAGRAM 2 21 Rear brake right side view ...
Page 62: ...CABLE ROUTING DIAGRAM 2 23 ...
Page 158: ...CHAIN DRIVE 4 66 ...
Page 202: ...CRANKSHAFT 5 42 seal lip 4 1 2 3 M ...
Page 226: ...CARBURETOR 7 11 ...
Page 231: ...ELECTRICAL COMPONENTS 8 4 EAM30289 CHECKING THE SWITCHES 1 1 Engine stop switch ...
Page 236: ...ELECTRICAL COMPONENTS 8 9 ...
Page 250: ...TROUBLESHOOTING 9 13 ...
Page 268: ......