Yamaha YP125R Service Manual

REAR BRAKE
4-37
EAS22560
INTRODUCTION
WARNING
EWA14101
Disc brake components rarely require disas-
sembly. Therefore, always follow these pre-
ventive measures:
• Never disassemble brake components un-
less absolutely necessary.
• If any connection on the hydraulic brake
system is disconnected, the entire brake
system must be disassembled, drained,
cleaned, properly filled, and bled after reas-
sembly.
• Never use solvents on internal brake com-
ponents.
• Use only clean or new brake fluid for clean-
ing brake components.
• Brake fluid may damage painted surfaces
and plastic parts. Therefore, always clean
up any spilt brake fluid immediately.
• Avoid brake fluid coming into contact with
the eyes as it can cause serious injury.
FIRST AID FOR BRAKE FLUID ENTERING
THE EYES:
• Flush with water for 15 minutes and get im-
mediate medical attention.
EAS22570
CHECKING THE REAR BRAKE DISC
1. Remove:
• Rear wheel
Refer to “REAR WHEEL” on page 4-15.
2. Check:
• Brake disc
Damage/galling → Replace.
3. Measure:
• Brake disc deflection
Out of specification → Correct the brake disc
deflection or replace the brake disc.
Refer to “CHECKING THE FRONT BRAKE
DISC” on page 4-22.
4. Measure:
• Brake disc thickness
Measure the brake disc thickness at a few dif-
ferent locations.
Out of specification → Replace.
Refer to “CHECKING THE FRONT BRAKE
DISC” on page 4-22.
5. Adjust:
• Brake disc deflection
Refer to “CHECKING THE FRONT BRAKE
DISC” on page 4-22.
6. Install:
• Rear wheel
Refer to “REAR WHEEL” on page 4-15.
EAS37P1131
REPLACING THE REAR BRAKE PADS
(YP125R)
T
IP
When replacing the brake pads, it is not neces-
sary to disconnect the brake hose or disassem-
ble the brake caliper.
1. Measure:
• Brake pad wear limit “a”
Out of specification → Replace the brake
pads as a set.
2. Install:
• Brake pad spring
• Brake pads
Brake disc deflection limit
0.25 mm (0.0098 in) (YP125R)
0.15 mm (0.0059 in) (YP250R)
Brake disc thickness limit
4.5 mm (0.18 in)
T
R
.
.
Rear brake disc bolt
23 Nm (2.3 m·kgf, 17 ft·lbf)
LOCTITE®
Brake pad lining thickness (in-
ner)
7.3 mm (0.29 in)
Limit
0.8 mm (0.03 in)
Brake pad lining thickness (out-
er)
7.3 mm (0.29 in)
Limit
0.8 mm (0.03 in)
a
New
New

Yamaha YP125R Specifications

General

Engine Type	Liquid-cooled, 4-stroke, SOHC, 4-valve
Bore x Stroke	52.4 mm x 57.9 mm
Fuel System	Fuel Injection
Ignition System	TCI
Transmission	V-Belt Automatic
Front Suspension	Telescopic fork
Rear Suspension	Unit Swing
Front Brake	Hydraulic single disc, Ø267 mm
Starter System	Electric
Rear Tyre	140/70-14M/C 62P (Tubeless)