6.2.2 Description and Operation
6.2.2.1 Description and Operation

Front Disc Brake System Components:

Front disc brake system consists of the following components:

Brake  Pad:Apply  the  force  from  the  hydraulic  brake  caliper
mechanical output on the brake disc friction surface.

Brake Pad Guide:Installed between the the disc brake pad and
the brake pad mounting bracket to keep the brake pad moving
smooth and to eliminate the noise.

Brake  Disk:The  disc  brake  pad  and  the  brake  disc  surface
friction  mechanical  output  slows  down  the  tires  and  wheels
assembly rotation speed, enables the vehicle's braking.

Brake Caliper:Receive the hydraulic pressure from the brake
master cylinder, converts the hydraulic pressure to mechanical
output  force  acting  on  the  brake  pads;  When  the  master
cylinder returns its position, the brake caliper piston returns to
its position.

Brake Caliper and Brake Pad Mounting Bracket:It is used to fix
the disc brake pad and brake caliper in place to maintain the
correct correlation with the hydraulic brake caliper. When the
mechanical output is applied on the brake pad, it makes the
brake pad slide.

Brake  Caliper  Floating  Pin:It  is  used  to  install  the  hydraulic
brake  caliper,  fix  the  brake  caliper  in  place  to  maintain  the
correct  correlation  with  the  with  the  brake  caliper  bracket.
When the mechanical output is applied on the brake caliper, it
makes the the brake caliper slide in relation to the brake pad.

Front Disc Brake System Operation:

The mechanical output from the hydraulic brake caliper piston
is applied on the brake pad. When the piston pushes the inside
brake pad from outside, at the same time, the brake caliper
pulls the outer brake pads inward, so that the output power is
evenly distributed. The brake pad applies the output force to
the brake disc friction surface on both sides, thus slowing down
the tire and wheel assembly speed. Whether the brake lining
guide and the floating brake caliper pin are working properly is
very important to evenly distribute the braking force.

Brake System

Front Brake

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6.2.3 Disassemble View
6.2.3.1 Disassemble View

5

1

3

2

4

6

7

8

9

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Legend

1. Brake Pad Guide
2. Brake Pad
3. Brake Caliper Mounting Bracket
4. Floating Pin Seal
5. Brake Caliper
6. Steering Knuckle

7. Disc Brake Dust Cover
8. Wheel Hub Assembly
9. Brake Disc

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Front Brake

Brake System

6.2.4 Diagnostic Information and Procedures
6.2.4.1 Brake Pad Inspection

1. Regularly check the brake pad, measure the brake pad according to the graphic shown below. If the measurement is not within

the specification, replace the brake pad.

2. If the brake pad needs to be replaced, replace the disc brake pads on the same axle at the same time.

3. Check whether the disc brake pad friction surface is cracked, broken or damaged.

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6.2.4.2 Brake Caliper Inspection

1. Check whether the brake caliper housing is cracking, severely worn or damaged. If the above conditions exist, replace the brake

caliper.

2. Check whether the brake caliper piston dust cover seal is cracked, broken, punctured, aging, and improperly installed in the

brake caliper body. If there is any of the above conditions, replace the brake caliper.

3. Check whether there is brake fluid leak on the brake caliper piston dust cover seal surrounding and the disc brake pad. If there

is brake fluid leaking sign, replace the brake caliper.

4. Check whether the brake caliper piston enters into the caliper cylinder smoothly and completely. The movement should be

smooth. If the brake caliper piston is stuck or hard to reach the cylinder bottom, replace the brake caliper.

6.2.4.3 Brake Guide Inspection

–

Check the brake guide for the existence of deficiencies, severe corrosion, installing convex tongue bent.

–

If any of the above is found, replace the disc brake guide. Make sure that the brake pad slide smoothly on the disc brake pad
guide without blocking.

6.2.4.4 Floating Brake Caliper Pin Inspection

Check the brake caliper pin floating whether the following conditions exist:

–

Catching

–

Stuck

–

Jacket Cracking or Broken

–

Jacket Missing

Brake System

Front Brake

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If any of the above is found, replace the brake caliper and the dust cover seal.

6.2.4.5 Brake Disc Surface and Worn Inspection

1. Clean the brake disc brake friction surface with industrial alcohol or a permitted equivalent detergent.

2. Check the brake disc friction surface for the following conditions:

•

Severe corrosion and / or pitting

•

Minor Surface Rust

•

Cracking and / or Sunburn

•

Serious Color Changing (Blue)

•

Deep scratches on the brake disc friction surface

If one or more of the above exists, then the brake disc needs to be repaired or replaced.

Note

After the brake disk surface repair or replacement, the brake pad needs to be replaced.

6.2.4.6 Brake Disc Thickness Measurement

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1. Clean the brake disc brake friction surface with industrial alcohol or similar cleaning agent .

2. With a micrometer to measure and record evenly distributed 4 or more points minimum thickness along the circumference of the

brake disc. Make sure that only measure the brake pad lining contacting area. For each measurement, the micrometer and the
brake disc outer edge distance must be equal.

3. If the brake disc thickness exceeds the specifications, replace the brake disc.

Note

After the brake disk repair or replacement, the brake pad should be replaced.

6.2.4.7 Brake Disc Assembly Rear Face Run Out Measurement

Note

When removing the brake disc from the wheel hub / axle flange, remove the rust or dirt from the wheel hub / axle flange
and the brake disc mating surface, otherwise, it could lead to brake disc assembly rear face excessive run out, lead to
the brake pulsation.

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Front Brake

Brake System