Yamaha YZF-R125 Service Manual: Replacing the front brake pads
NOTE:
When replacing the brake pads, it is not necessary to disconnect the brake hose or disassemble the brake caliper.
1. Measure:
- Brake pad wear limit "a"
Out of specification
Replace
the brake pads as a set.
2. Install:
- Brake pad support
- Brake pad spring
- Brake pads
NOTE:
Always install new brake pads, a new brake pad spring and a new brake pad support as a set.
a. Connect a clear plastic hose "1" tightly to the bleed screw "2". Put the other end of the hose into an open container.
b. Loosen the bleed screw and push the brake caliper pistons into the brake caliper with your fingers.
c. Tighten the bleed screw. 
d. Install new brake pad support, a new brake pad spring and new brake pads.
NOTE:
The arrow mark "a" on the brake pad spring must point in the direction of disc rotation.
3. Install:
- Brake pad pin
- Brake pad clips
- Front brake caliper
4. 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.
5. Check:
- Brake lever operation
Soft or spongy feeling
Bleed
the brake system.Refer to "BLEEDING THE HYDRAULIC BRAKE SYSTEM" on page 3-20.
Checking the front brake disc
1. Remove:
Front wheel
Refer to "FRONT WHEEL" on page 4-6.
2. Check:
Brake disc
Damage/galling Replace.
3. Measure:
Brake disc deflection
Out of specification Correct the
b ...
Removing the front brake caliper
NOTE:
Before disassembling the brake caliper, drain
the brake fluid from the entire brake system.
1. Remove:
Brake hose union bolt "1"
Copper washers "2"
Brake hose "3"
NOTE:
Put the en ...
Other materials:
Checking the cooling system
1. Remove:
Side covers
Upper side cowlings
Refer to "GENERAL CHASSIS" on page 4-1.
2. Check:
Radiator "1"
Radiator inlet hose "2"
Radiator outlet hose "3"
Coolant reservoir hose "4"
Water pump breather hose "5"
Cracks/damage → Replace.
Refer to "RADIATOR" on page 6-1 ...
Checking the crankshaft position sensor
1. Disconnect:
Crankshaft position sensor coupler
(from the wire harness)
2. Check:
Crankshaft position sensor resistance
Out of specification Replace
the crankshaft
position sensor/stator assembly.
a. Connect the pocket tester ( × 100) to the
crankshaft position sensor c ...
Replacing the air filter element and cleaning the check hose
The air filter element should be replaced
at the intervals specified in the
periodic maintenance and lubrication
chart. Have a Yamaha dealer replace
the air filter element more frequently if
you are riding in unusually wet or dusty
areas. In addition, the air filter check
hose must be ...