Yamaha YZF-R125 Service Manual: Replacing the rear brake pads
NOTE:
When replacing the brake pads, it is not necessary to disconnect the brake hose or disassemble the brake caliper.
1. Remove:
- Brake pads
- Brake pad spring
NOTE:
To remove the inner brake pad "1", push down on the brake caliper bracket so that there is space to remove the brake pad.
2. Measure:
Brake pad wear limit "a"
Out of specification → Replace the brake
pads as a set. 
3. Install:
- Brake pad spring
- Brake pads
NOTE:
Always install new brake pads and a new brake pad spring as a set.
a. Connect a clear plastic hose tightly to the bleed screw. Put the other end of the hose into an open container.
b. Loosen the bleed screw and push the brake caliper piston into the brake caliper with your finger.
c. Tighten the bleed screw. 
d. Install a new brake pad spring "1" and new brake pads.
NOTE:
Install the brake pad spring as shown.
4. Install:
- Brake pad retaining bolts
- Brake caliper
5. Install:
- Rear wheel Refer to "REAR WHEEL" on page 4-12.
6. 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 3-18.
7. Check:
- Brake pedal operation
Soft or spongy feeling Bleed
the brake system.Refer to "BLEEDING THE HYDRAULIC BRAKE SYSTEM" on page 3-20.
Checking the rear brake disc
1. Remove:
Rear wheel
Refer to "REAR WHEEL" on page 4-12.
2. Check:
Brake disc
Damage/galling → Replace.
3. Measure:
Brake disc deflection
Out of specification → Correc ...
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 th ...
Other materials:
Checking the ignition timing
NOTE:
Prior to checking the ignition timing, check the
wiring connections of the entire ignition system.
Make sure all connections are tight and free of
corrosion.
1. Remove:
Rider seat
Left lower side cowling
Refer to "GENERAL CHASSIS" on page 4-1.
2. Remove:
Timing mark acces ...
Checking the clutch housing
1. Check:
Clutch housing dogs "1"
Damage/pitting/wear
Deburr the clutch
housing dogs or replace the clutch housing.
NOTE:
Pitting on the clutch housing dogs will cause erratic
clutch operation.
2. Check:
Bearing
Damage/wear Replace the
bearing and
clutch housin ...
Checking the switches
1. Clutch switch
2. Main switch
3. Front brake light switch
4. Sidestand switch
5. Rear brake light switch
6. Neutral switch
7. Turn signal switch
8. Horn switch
9. Dimmer switch
10.Pass switch
11.Engine stop switch
12.Start switch
Check each switch for continuity with the pocket tes ...