Yamaha YZF-R125 Service Manual: Installing the water pump
1. Install:
- Water pump assembly "1"
- O-rings "2"
NOTE:
- Align the projection "a" on the impeller shaft with the slit "b" on the camshaft sprocket bolt.
- Lubricate the O-rings with a thin coat of lithiumsoap- based grease.
2. Fill:
- Cooling system (with the specified amount of the recommended coolant)
Refer to "CHANGING THE COOLANT" on page 3-15.
3. Check:
Cooling system
Leaks 
Repair or replace the faulty
part.
4. Measure:
Radiator cap opening pressure
Below the specified pressure
Replace the
radiator cap.
Refer to "CHECKING THE RADIATOR" on page 6-3.
Assembling the water pump
1. Install:
Water pump seal "1"
(into the water pump housing "2")
CAUTION:Never lubricate the water pump seal
surface
with oil or grease.
NOTE:
Install the water pump ...
Fuel system
...
Other materials:
Removing the rear brake caliper
NOTE:
Before disassembling the brake caliper, drain
the brake fluid from the entire brake system.
1. Remove:
Union bolt "1"
Copper washers "2"
Brake hose "3"
NOTE:
Put the end of the brake hose into a container
and pump out the brake fluid carefully. ...
Bearings and oil seals
Install bearings "1" and oil seals "2" so that the
manufacturer's marks or numbers are visible.
When installing oil seals "1", lubricate the oil seal
lips with a light coat of lithium-soap-based
grease. Oil bearings liberally when installing, if
appropriate.
CAUTION:Do not spin th ...
Checking the turn signal relay
1. Check:
Turn signal relay input voltage
Out of specification →The wiring circuit
from
the main switch to the turn signal relay coupler
is faulty and must be repaired.
a. Connect the pocket tester (DC 20 V) to the
turn signal relay terminal as shown.
- Positive tester probe
b ...