Checking The Front Brake Master Cylinder - Yamaha 2009 YZF-R1 (Y) Service Manual

Recommended 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 perfor-
mance.
• 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
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 3-17.
5. Check:
• Brake fluid level
Below the minimum level mark "a" → Add
the recommended brake fluid to the
proper level.
Refer to "CHECKING THE BRAKE
FLUID LEVEL" on page 3-15.
6. Check:
• Brake lever operation
Soft or spongy feeling → Bleed the brake
system.
Refer to "BLEEDING THE HYDRAULIC
BRAKE SYSTEM" on page 3-17.
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. Disconnect:
• Front brake light switch connectors "1"
(from the brake switch)
2. Remove:
• Union bolt "2"
• Washers "3"
• Brake hose "4"
TIP
To collect any remaining brake fluid, place a
container under the master cylinder and the
end of the brake hose.
3. Remove:
• Brake master cylinder holder
• Brake master cylinder
EAS22510
CHECKING THE FRONT 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.
4-40
FRONT BRAKE