Yamaha YZF-R125 Service Manual: Installing the front brake caliper

Yamaha YZF-R125 Service Manual / Chassis / Front brake / Installing the front brake caliper

1. Install:

Brake caliper "1" (temporarily)
Copper washers "2"

Brake hose "3"
Brake hose union bolt "4"

WARNING

Proper brake hose routing is essential to insure safe vehicle operation. Refer to "CABLE ROUTING" on page 2-33.

CAUTION:

Install the brake hose at a 17 angle to the front brake caliper as shown in the illustration.
While holding the brake hose, tighten the union bolt.

Installing the front brake caliper

2. Remove:

Brake caliper

3. Install:

Brake pad spring
Brake pads
Brake caliper
Brake hose holder

Refer to "REPLACING THE FRONT BRAKE PADS" on page 4-22.

4. Fill:

Brake master cylinder reservoir (with the specified amount of the recommended brake fluid)

WARNING

Use only the designated brake fluid. Other brake fluids may cause the rubber seals to deteriorate, causing leakage and poor brake performance.
Refill with the same type of brake fluid that is already in the system. Mixing brake fluids may result in a harmful chemical reaction, leading to poor brake performance.
When refilling, be careful that water does not enter the brake master cylinder reservoir.

Water will significantly lower the boiling point of the brake fluid and could cause vapor lock.

CAUTION:

Brake fluid may damage painted surfaces and plastic parts. Therefore, always clean up any spilt brake fluid immediately.

5. Bleed:

Brake system Refer to "BLEEDING THE HYDRAULIC BRAKE SYSTEM" on page 3-20.

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.

Installing the front brake caliper

7. Check:

Brake lever operation Soft or spongy feeling → Bleed the brake system.

Refer to "BLEEDING THE HYDRAULIC BRAKE SYSTEM" on page 3-20.

Assembling the front brake caliper

WARNING Before installation, all internal brake components should be cleaned and lubricated with clean or new brake fluid. Never use solvents on internal brake components as ...

Removing the front brake master cylinder

NOTE: Before removing the front brake master cylinder, drain the brake fluid from the entire brake system. 1. Disconnect: Front brake light switch 2. Remove: Brake hose union bolt Copp ...

Other materials:

Installing the valves
The following procedure applies to all of the valves and related components. 1. Deburr: Valve stem end (with an oil stone) 2. Lubricate: Valve stem "1" Valve stem seal "2" (with the recommended lubricant) 3. Install: Lower spring seat "1" Valve stem seal "2" V ...

Checking the cylinder and piston
1. Check: Piston wall Cylinder wall Vertical scratches Replace the cylinder, and replace the piston and piston rings as a set. 2. Measure: Piston-to-cylinder clearance a. Measure cylinder bore "C" with the cylinder bore gauge. NOTE: Measure cylinder bore "C" by takin ...

Bleeding the hydraulic brake system
WARNINGBleed the hydraulic brake system whenever: the system is disassembled. a brake hose is loosened, disconnected or replaced. the brake fluid level is very low. brake operation is faulty. NOTE: Be careful not to spill any brake fluid or allow th ...