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:

Checking the front brake caliper
1. Check: Brake caliper pistons "1" Rust/scratches/wear Replace the brake caliper assembly. Brake caliper body "2" Cracks/damage Replace the brake caliper assembly. Brake fluid delivery passages (brake caliper body) Obstruction Blow out with compressed air. ...

Checking the rectifier/regulator
1. Check: Rectifier/regulator output voltage Out of specification → Replace the rectifier/ regulator. a. Set the engine tachometer to the spark plug lead. b. Connect the pocket tester (DC 20 V) to the rectifier/regulator coupler as shown. Positive tester probe red "1" Negat ...

Checking the ignition spark gap
1. Check: Ignition spark gap Out of specification Perform the ignition system troubleshooting, starting with step 5. Refer to "TROUBLESHOOTING" on page 8-3. NOTE: If the ignition spark gap is within specification, the ignition system circuit is operating normally. a. Disconnect the spa ...