Yamaha XMAX YP125R - Service manual > Removing the rear brake caliper

TIP

Before removing the brake caliper, drain the brake fluid from the entire brake system.

1. Remove:

• Brake hose union bolt "1"
• Copper washers "2"
• Rear brake hose "3"

TIP

Put the end of the brake hose into a container and pump out the brake fluid carefully.

A. YP125R

B. YP250R

Disassembling the rear brake caliper (YP250R only)

1. Remove:

• Brake caliper pistons "1"
• Brake caliper piston dust seals "2"
• Brake caliper piston seals "3"

a. Blow compressed air into the brake hose joint opening "a" to force out the pistons from the brake caliper.

WARNING

• Cover the brake caliper piston with a rag.

  Be careful not to get injured when the piston is expelled from the brake caliper.

• Never try to pry out the brake caliper piston.

b. Remove the brake caliper piston dust seals and brake caliper piston seals.

Checking the rear brake caliper (YP125R)

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 rear brake caliper (YP250R)

1. Check:

• Brake caliper pistons "1"

Rust/scratches/wear → Replace the brake caliper pistons.

• Brake caliper cylinders "2"

Scratches/wear → Replace the brake caliper assembly.

• Brake caliper body "3"

Cracks/damage → Replace the brake caliper assembly.

• Brake fluid delivery passages

(brake caliper body) Obstruction → Blow out with compressed air.

WARNING

Whenever a brake caliper is disassembled, replace the brake caliper piston dust seals and brake caliper piston seals.

2. Check:

• Brake caliper bracket

Cracks/damage → Replace.

Assembling the rear 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 they will cause the brake caliper piston dust seals and brake caliper piston seals to swell and distort (YP250R only).
• Whenever a brake caliper is disassembled, replace the brake caliper piston dust seals and brake caliper piston seals (YP250R only).

Recommended fluid DOT 4

Installing the rear brake caliper (YP125R)

1. Install:

• Rear brake caliper "1" (temporarily)
• Copper washers "2"
• Rear brake hose "3"
• Brake hose union bolt "4"

Brake hose union bolt 28 Nm (2.8 m*kgf, 20 ft*lbf)

WARNING

Proper brake hose routing is essential to insure safe vehicle operation.

NOTICE

While holding the brake hose, tighten the union bolt within the angle range shown in the illustration.

2. Remove:

• Rear brake caliper

3. Install:

• Brake pad spring
• Brake pads
• Brake pad pin
• Brake pad clip
• Rear brake caliper

Rear brake caliper bolt 40 Nm (4.0 m*kgf, 29 ft*lbf)

4. Fill:

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

Recommended fluid DOT 4

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.

NOTICE

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

5. Bleed:

• Brake system

6. Check:

• Brake fluid level

Below the minimum level mark "a" → Add the recommended brake fluid to the proper level.

7. Check:

• Brake lever operation

Soft or spongy feeling → Bleed the brake system.

See also: