Yamaha YZF-R125 Service Manual: Bleeding the hydraulic brake system
| WARNING Bleed the hydraulic brake system whenever:
|
NOTE:
- Be careful not to spill any brake fluid or allow the brake master cylinder reservoir or brake fluid reservoir to overflow.
- When bleeding the hydraulic brake system, make sure there is always enough brake fluid before applying the brake. Ignoring this precaution could allow air to enter the hydraulic brake system, considerably lengthening the bleeding procedure.
- If bleeding is difficult, it may be necessary to let the brake fluid settle for a few hours. Repeat the bleeding procedure when the tiny bubbles in the hose have disappeared.
1. Bleed:
- Hydraulic brake system
a. Fill the brake fluid reservoir to the proper level with the recommended brake fluid.
b. Install the diaphragm (brake master cylinder reservoir or brake fluid reservoir).
c. Connect a clear plastic hose "1" tightly to the bleed screw "2".
A. Front
B. Rear
d. Place the other end of the hose into a container.
e. Slowly apply the brake several times.
f. Fully pull the brake lever or fully press down the brake pedal and hold it in position.
g. Loosen the bleed screw.
NOTE:
Loosening the bleed screw will release the pressure and cause the brake lever to contact the throttle grip or the brake pedal to fully extend.
h. Tighten the bleed screw and then release the brake lever or brake pedal.
i. Repeat steps (e) to (h) until all of the air bubbles have disappeared from the brake fluid in the plastic hose.
j. Tighten the bleed screw to specification.
k. Fill the brake fluid reservoir to the proper level with the recommended brake fluid.
Refer to "CHECKING THE BRAKE FLUID LEVEL" on page 3-18.
| WARNING After bleeding the hydraulic brake system, check the brake operation. |
Checking the rear brake hose
1. Check:
Brake hoses "1"
Cracks/damage/wear
Replace.
2. Check:
Brake hose holder "2"
Loose connection Tighten the
holder bolt.
Loose or open holder Fasten
properly ...
Adjusting the drive chain slack
NOTE:
The drive chain slack must be checked at the
tightest point on the chain.
CAUTION:A drive chain that is too tight will
overload
the engine and other vital parts, and one that
...
Other materials:
Checking the fuel pressure
1. Check:
Pressure regulator operation
a. Remove the fuel hose connector cover "1"
and disconnect the fuel hose "2" from the fuel
pump.
CAUTION:Although the fuel has been removed from
the fuel tank, be careful when removing the
fuel hose, since there may be fuel remaining
i ...
Changing the engine oil
1. Remove:
Right bottom cowling
Right upper side cowling
Right lower side cowling
Refer to "GENERAL CHASSIS" on page 4-1.
2. Start the engine, warm it up for several minutes,
and then turn it off.
3. Place a container under the engine oil drain
bolt.
4. Install:
Engine oil d ...
Drive chain slack
The drive chain slack should be
checked before each ride and adjusted
if necessary.
To check the drive chain slack
Place the motorcycle on the sidestand.
TIP
When checking and adjusting the drive
chain slack, there should be no weight
on the motorcycle.
Shift the transmission in ...