Yamaha Tracer MT09TRA - Service manual > Front brake

Introduction

WARNING

Disc brake components rarely require disassembly.

Therefore, always follow these preventive measures:

• Never disassemble brake components unless 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 reassembly.
• Never use solvents on internal brake components.
• Use only clean or new brake fluid for cleaning 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 immediate medical attention.

Checking the front brake discs

The following procedure applies to both brake discs.

1. Remove:

• Front wheel

2. Check:

• Front brake disc
• Damage/galling → Replace.

3. Measure:

• Brake disc runout

Out of specification → Correct the brake disc runout or replace the brake disc.

Brake disc runout limit (as measured on wheel) 0.10 mm (0.0039 in)

a. Place the vehicle on a suitable stand so that the front wheel is elevated.

b. Before measuring the brake disc runout, turn the handlebar to the left or right to ensure that the front wheel is stationary.

c. Remove the brake caliper.

d. Hold the dial gauge at a right angle against the brake disc surface.

e. Measure the runout 1.5 mm (0.06 in) below the edge of the brake disc.

4. Measure:

• Brake disc thickness

Measure the brake disc thickness at a few different locations.

Out of specification →  Replace.

Brake disc thickness limit 4.0 mm (0.16 in)

5. Adjust:

• Brake disc runout

a. Remove the brake disc.

b. Rotate the brake disc by one bolt hole.

c. Install the brake disc.

Front brake disc bolt 18 Nm (1.8 m*kgf, 13 ft*lbf) LOCTITE

NOTICE

Replace the brake disc bolts with new ones.

TIP

Tighten the brake disc bolts in stages and in a crisscross pattern.

d. Measure the brake disc runout.

e. If out of specification, repeat the adjustment steps until the brake disc runout is within specification.

f. If the brake disc runout cannot be brought within specification, replace the brake disc.

6. Install:

• Front wheel

Replacing the front brake pads

The following procedure applies to both brake calipers.

TIP

When replacing the brake pads, it is not necessary to disconnect the brake hose or disassemble the brake caliper.

1. Remove:

• Brake pad clips "1"
• Brake pad pin "2"
• Brake pad spring "3"

2. Remove:

• Brake pads "1"

3. Measure:

• Brake pad wear limit "a"

Out of specification → Replace the brake pads as a set.

Brake pad lining thickness (inner) 4.5 mm (0.18 in)

Limit 0.5 mm (0.02 in)

Brake pad lining thickness (outer) 4.5 mm (0.18 in)

Limit 0.5 mm (0.02 in)

4. Remove:

• Brake caliper bolts

5. Install:

• Brake pads
• Brake pad spring

TIP

Always install new brake pads and new brake pad spring 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 finger.

c. Tighten the bleed screw.

Brake caliper bleed screw 5 Nm (0.5 m*kgf, 3.6 ft*lbf)

d. Install the brake pads and brake pad spring.

TIP

The arrow mark "a" on the brake pad spring must point in the direction of disc rotation.

6. Install:

• Brake pad pin
• Brake pad clips
• Front brake caliper

Front brake caliper bolt 35 Nm (3.5 m*kgf, 25 ft*lbf)

7. Check:

• Brake fluid level

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

Refer to "CHECKING THE BRAKE FLUID LEVEL"

8. Check:

• Brake lever operation

Soft or spongy feeling →  Bleed the brake system.

Refer to "BLEEDING THE HYDRAULIC BRAKE SYSTEM (ABS)"

Removing the front brake calipers

The following procedure applies to both of the brake calipers.

TIP

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

1. Remove:

• Brake hose union bolts "1"
• Brake hose gaskets "2"
• Brake hoses "3"

TIP

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

Disassembling the front brake calipers

The following procedure applies to both of the brake calipers.

1. Remove:

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

a. Secure the right side brake caliper pistons with a piece of wood "a".

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

WARNING

• Never try to pry out the brake caliper pistons.
• Do not loosen the bolts "4".

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

d. Repeat the previous steps to force out the right side pistons from the brake caliper.

Checking the front brake calipers

The following procedure applies to both of the brake calipers.

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.

Assembling the front brake calipers

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

  Specified brake fluid DOT 4

Installing the front brake calipers

The following procedure applies to both of the brake calipers.

1. Install:

• Front brake caliper "1" (temporarily)
• Brake hose gaskets
• Brake hoses "2"
• Brake hose union bolts "3"

Front brake hose union bolt 30 Nm (3.0 m*kgf, 22 ft*lbf)

WARNING

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

NOTICE

• When installing the brake hose onto the brake caliper "1", make sure the brake pipe "a" touches the projection "b" on the brake caliper.
• Install the brake pipe "c" so that it is aligned with the brake pipe "a".

2. Remove:

• Front brake caliper

3. Install:

• Brake pads
• Brake pad spring
• Brake pad pin
• Brake pad clips
• Front brake caliper

Front brake caliper bolt 35 Nm (3.5 m*kgf, 25 ft*lbf)

Refer to "REPLACING THE FRONT BRAKE PADS"

4. Fill:

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

Specified brake 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 fluid 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

Refer to "BLEEDING THE HYDRAULIC BRAKE SYSTEM (ABS)"

6. Check:

• Brake fluid level

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

Refer to "CHECKING THE BRAKE FLUID LEVEL"

7. Check:

• Brake lever operation

Soft or spongy feeling → Bleed the brake system.

Refer to "BLEEDING THE HYDRAULIC BRAKE SYSTEM (ABS)"

Removing the front brake master cylinder

TIP

Before removing the front brake master cylinder, drain the brake fluid from the entire brake system.

1. Disconnect:

• Brake light switch connectors (from the front brake light switch)

2. Remove:

• Brake hose union bolt "1"
• Brake hose gaskets "2"
• Brake hose "3"

TIP

To collect any remaining brake fluid, place a container under the master cylinder and the end of the brake hose.

Checking the front brake master cylinder

1. Check:

• Brake master cylinder

Damage/scratches/wear → Replace.

• Brake fluid delivery passages

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

2. Check:

• Brake master cylinder kit

Damage/scratches/wear → Replace.

3. Check:

• Brake master cylinder reservoir "1"
• Brake master cylinder reservoir diaphragm holder "2"
• Cracks/damage →  Replace.
• Brake master cylinder reservoir diaphragm "3"

Damage/wear → Replace.

4. Check:

• Brake hoses

Cracks/damage/wear →  Replace.

Assembling the front brake master cylinder

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.

Specified brake fluid DOT 4

Installing the front brake master cylinder

1. Install:

• Front brake master cylinder
• Front brake master cylinder holder

Front brake master cylinder holder bolt 10 Nm (1.0 m*kgf, 7.2 ft*lbf)

TIP

• Install the front brake master cylinder holder with the "UP" mark "a" facing up.
• Align the end of the front brake master cylinder holder with the punch mark "b" on the handlebar.
• First, tighten the upper bolt, then the lower bolt.
• There should be more than 11 mm (0.43 in) for clearance between the right handlebar switch and the front brake master cylinder holder. Also, the punch mark should be seen.

2. Install:

• Brake hose gaskets
• Brake hose
• Brake hose union bolt

Front brake hose union bolt 30 Nm (3.0 m*kgf, 22 ft*lbf)

WARNING

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

TIP

• Attach the brake hose so that its angle is 3º to 13º against the straight line in parallel with the ceiling plane of the master cylinder.
• While holding the brake hose, tighten the union bolt as shown.
• Turn the handlebar to the left and right to make sure the brake hose does not touch other parts (e.g., wire harness, cables, leads). Correct if necessary.

3. Fill:

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

Specified brake 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.

4. Bleed:

• Brake system

Refer to "BLEEDING THE HYDRAULIC BRAKE SYSTEM (ABS)"

5. Check:

• Brake fluid level

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

Refer to "CHECKING THE BRAKE FLUID LEVEL"

6. Check:

• Brake lever operation

Soft or spongy feeling → Bleed the brake system.

Refer to "BLEEDING THE HYDRAULIC BRAKE SYSTEM (ABS)"

See also: