Removing/Checking The Rear Brake Master Cylinder - Yamaha YZF-R25 Service Manual

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.
4. Bleed:
• Brake system
Refer to "BLEEDING THE HYDRAULIC
BRAKE SYSTEM" on page 3-14.
5. Check:
• Brake fluid level
Below the minimum level mark "a" → Add the
specified brake fluid to the proper level.
Refer to "CHECKING THE BRAKE FLUID
LEVEL" on page 3-15.
6. Check:
• Brake pedal operation
Soft or spongy feeling → Bleed the brake sys-
tem.
Refer to "BLEEDING THE HYDRAULIC
BRAKE SYSTEM" on page 3-14.
EAS30193
REMOVING THE REAR BRAKE MASTER
CYLINDER
1. Remove:
• Brake hose union bolt "1"
• Brake hose gaskets "2"
• Brake hose "3"
a
4-52
TIP
To collect any remaining brake fluid, place a
container under the master cylinder and the end
of the brake hose.
EAS30194
CHECKING THE REAR BRAKE MASTER
CYLINDER
1. Check:
• Brake master cylinder
Damage/scratches/wear → Replace.
• Brake fluid delivery passages
(brake master cylinder body)
Obstruction → Blow out with compressed air.
2. Check:
• Brake master cylinder kit
Damage/scratches/wear → Replace.
3. Check:
• Brake fluid reservoir "1"
• Brake fluid reservoir diaphragm holder "2"
Cracks/damage → Replace.
• Brake fluid reservoir diaphragm "3"
Damage/wear → Replace.
2
4. Check:
• Brake hose
• Brake fluid reservoir hose
Cracks/damage → Replace.
REAR BRAKE
1
2
3
3
1