2008 GREAT WALL FLORID steering

Downloaded from www.Manualslib.com manuals search engine 95Brake System
Brake System Components Arrangement Schematics
Brake pedal assembly
Vacuum booster with brake cylinder assembly
Left steering knuckle and hub brake assembly
Left parking brake cable assembly
Rear brake assembly RHRear brake drum
Rear wheel speed sensor assembly RH
Right parking brake cable assembly
ABS controller assembly
Right steering knuckle and hub brake assembly
Brake line assembly
Rear wheel speed
sensor assembly LH
Front wheel speed sensor assembly RHFront wheel speed sensor assembly LH
Rear brake assembly LH
Parking brake control mechanism assembly

Downloaded from www.Manualslib.com manuals search engine 107Brake System
Anti-lock Brake System
ABS/EBD introduction
1. Operation
The vehicle's Anti-lock Brake System (ABS) is a type of increasingly popular brake safety device. It detects the
wheel's speed using wheel speed sensor detection. After signal processing, the wheel speed will be transferred
to the computer, which controls the solenoid valve’s operating condition and the pressure inside the brake wheel
cylinder to avoid wheel locking by using certain calculations and control methods based on the wheel speed.
ABS helps the vehicle to avoid sliding, deviation, fishtailing, and losing steering control capacity. ABS improves
the vehicle’s handling capability, stability and shortens braking distance. It also helps the vehicle to avoid the
partial wear and tear of wheels, hence improves the tire's useful life.
Electronic Brake Distribution (EBD) is used to adjust the vehicle's rear wheel brake pressure by using the ABS
components when the ABS does not respond to vehicle braking. It is also used to balance the vehicle’s front and
rear wheel brake pressure, maximizing the vehicle's braking efficiency. EBD uses the ABS components, yet its
controlling logic is independent from the ABS. After the ABS responds, the EBD will disengage.
2. Basic structure
3. ABS working process
(a) Pressure rising phase: While service braking, oil pressure output from the pump passes the inlet solenoid
valve and enters the brake wheel cylinder. The brake generates braking force and the wheel speed sharply
declines until the ABS control unit detects that the wheel is starting to lock via the wheel speed sensor
detection.
(b) Pressure maintaining phase: When the ABS control unit detects that the wheel is starting to lock via wheel
speed sensor signal, the inlet solenoid valve closes, with the outlet solenoid valve shut as usual. The
pressure maintaining phase thus begins.
(c) Pressure drop phrase: During the pressure maintaining phase, the wheels tend to lock further. This brings
the ABS into the pressure drop phrase. With the inlet valve closed and the outlet valve open, the hydraulic
pump starts working, and brake fluid returns to the brake pump from the wheel cylinder by passing through
the low pressure accumulator. The brake pressure reduces and the brake pedal bounces back.
(d) Pressure maintaining phase: With the degree of wheel locking decreases and wheel speed begins to
increase, the pressure maintaining phrase begins.
(e) Next cycle’s pressure rising phase: When the wheels reach a certain speed, the ABS enters the pressure rise
phase and starts the next cycle.
Note: The ABS's pressure adjusting frequency is generally 2 to 4 cycles per second.
ABS control unit
Wheel speed sensor
Wheel speed signal
Wheel cylinder
Valve work instruction
Hydraulic modulator
Vacuum booster & master cylinder

Downloaded from www.Manualslib.com manuals search engine GWFLORID Maintenance Manual108
4. EBD working process
The EBD comes into effect when the wheel brakes are lightly applied. The wheel speed sensor detects the speed
of the wheels, and the ECU calculates the speed. If the rear wheel's slip ratio increases, adjust the brake pressure
to maintain or reduce the rear wheel's braking force. The EBD guarantees the rear wheel's lateral force and even
brake force distribution. If the ABS fails to respond, the electronic brake distribution system can still adjust the
rear wheel's braking force to guarantee the rear wheels do not lock before the front wheels, in order to ensure
vehicle safety.
The EBD's working process for lifting and holding pressure is completely the same as it of the ABS working
process. However, the process for lowering pressure is quite different. When the rear wheel has a tendency to
lock up, the normally open valve of the rear wheel closes, the normally closed valve opens, and the rear wheel
pressure reduces. The difference with ABS is that the hydraulic pump does not operate at this time, and the brake
fluid released during depressurization is temporarily stored in the low pressure accumulator. After braking,the brake
pedal is loosened, and the brake pressure inside the pump drops to zero. Open the normally closed valve one more
time at this point. The brake fluid inside the low pressure accumulator returns to the pump by passing through the
normally closed valve and normally open valve. Empty the low pressure ac\
cumulator to prepare for the next brake.
ABS installation
1. Install the ABS controller assembly.
(a) Use three hexagon bolts for flange face (Q1840825) to
fix the ABS bracket assembly onto the vehicle body.
(b) Fix the shock pad of the ABS hydraulic pump onto the
mounting holes of the ABS bracket assembly.
(c) Insert the mount pin of the ABS controller assembly
into the shock pad holes by simply inserting the two
anchor pins into the bracket.
2. Install the ABS front wheel speed sensor with bracket
assembly.
(a) Use a hexagon head bolt, spring washer, and flat
washer subassembly to connect the sensor and the
steering knuckle.
(b) Use a hexagon head bolt and a flat washer subassembly
(M8) to connect the sensor bracket and the damper.
(c) Use a hexagon head bolt and a flat washer subassembly
(M6) to connect the sensor bracket and vehicle body.
ABS controller assembly
ABS hydraulic pressure pump shock pad
ABS mounting bracket assembly
Wheel speed sensor with bracket assembly
Steering knuckle
Propeller shaft
Wheel slippage
Vehicle speed
Wheel speed
Master cylinder pressure
Wheel cylinder brake pressure

Downloaded from www.Manualslib.com manuals search engine GWFLORID Maintenance Manual112
Steering Knuckle and Hub Brake Assembly
Components
Disposable parts
Steering knuckle and hub brake assembly
examination and disassembly
1. Hoist the vehicle and remove the wheels.
2. Loosen the riveted areas of the front drive shaft nut
and remove the nut.
3. Inspect the front brake disc plate surface runout.
When measuring, tighten the two wheel nuts' symmetrical
locations. The front brake disc's brake linings runout on the
two sides should be no more than 0.11 mm. If oversized,
they should be repaired or replaced.
4. Inspect front brake disc thickness.
Standard thickness: 22.0 mm
Minimum thickness: 20.0 mm
The brake disc must be changed when it reaches the minimum
level of thickness.
Front brake caliper assembly LH
Copper washer
Hollow bolt
♦Heavy duty spring washer
Snap ring for hole 72
♦Front hub
bearing assemblyLeft steering knuckle
Left brake disc cover
♦Hexagon head bolt and
spring washer subassembly
Wheel bolt
Front hub flange
Front brake disc
100 ± 10
: Specified torqueN·m
9 ± 2

Downloaded from www.Manualslib.com manuals search engine 113Brake System
5. Remove the front brake caliper.
Unscrew the fastened front brake caliper's bolt to remove the
brake caliper.
Caution: Remove the front brake caliper and use wire
or similar objects to firmly secure the brake caliper.
(Avoid excessive twisting, bending, or pulling off the
brake pipeline).
6. Remove the front brake disc.
After driving the vehicle for some time, it may be hard to
remove the brake discs. In this case, screw two M8 bolts
into the removed brake disc's threaded holes (refer to the left
picture for locations), and use a wrench to alternately turns
the two bolts, thereby ejecting the brake disc.
7. Inspect the front brake disc.
Inspect the wear and tear of the front brake disc. If the
brake disc has obvious scuffing, the plate surface runout
is oversized, or its thickness is smaller than the minimum
thickness, the brake disc should be replaced.
8. Remove the front brake disc cover.
Remove the fastened brake disc cover bolts with a wrench, and
remove the front brake disc cover.
9. Remove the steering knuckle's front hub bearing and
front hub flange assembly.
Suggestion: The steering knuckle's front hub bearing and
front hub flange assembly, under normal circumstances,
should not undergo disassembly. If determined to have a
problem, it should be replaced in its entirety.
10. Inspect the steering knuckle's front hub bearing and
front hub flange assembly.
(a) Use dye penetrant to inspect the steering knuckle for
cracks, deformities, and damage. If found, replace the
part.
(b) Rotate the front hub flange and examine the bearing for
flexible rotation. Also make sure there is no appearance
of clamping.
(c) Measure the front hub flange plate surface runout.
Caution: Runout should not exceed 0.03 mm.

Downloaded from www.Manualslib.com manuals search engine GWFLORID Maintenance Manual114
(d) Measure the front hub bearing's starting torque.
Put the SST on the wheel bolts which are at the symmetric
locations. Put a dial torque wrench on the SST to slowly
rotate the flange assembly (45°/4s), requiring a starting
torque range of 0.1-0.3 N·m.
If the bearing rotation is not flexible, the front hub flange
plate surface movement inaccurate, or front hub bearing
starting torque is too much. The assembly must be replaced.
Steering knuckle's front hub bearing and
front hub flange assembly
1. Removal and inspection of front hub flange assembly.
(a) Use SST like a hand held travel hammer to repeatedly
hammer off the front hub flange assembly from the
steering knuckle and front hub bearing. Remove the
front hub with bearing's inner ring.
(b) Remove the bearing's inner ring on the front hub.
Use SST to remove the bearing's inner ring.
SST
SST
Bearing inner ring
SST
(c) Use dye penetrant to inspect the front hub flange for
cracks, which should be replaced if found.
(d) If one would like to continue using the front hub flange
assembly, first inspect the dimensions for the mounting
area of the bearing for inaccurate dimensions. If
oversized, replace.
Measurement range: Φ38+0.025 +0.009 mm
2. Remove the steering knuckle's front hub bearing.
3. Remove the snap ring for hole 72.
Use a bent nose retaining ring caliper for holes to remove the
snap ring for hole 72.

Downloaded from www.Manualslib.com manuals search engine 115Brake System
4. Replace the removed bearing's inner ring back to the
bearing's original position.
5. Press out the front hub bearing from inside of the steer-
ing knuckle.
On the press, withstand the bearing inner ring that was put
on with SST, and press out the entire front hub bearing.
Caution: The front hub bearing assembly is a disposable
part, which needs to be replaced with a new one.
Steering knuckle and hub brake assembly
installation
1. On the press, press the front hub bearing assembly
into the steering knuckle hole bearing mounting posi-
tion with SST.
SST
SST
SST
6. If the steering knuckle has no cracks and one would
like to continue to use it, first inspect the bearing's
mounting location dimensions of the steering knuckle's
inner hole. If the measurements are oversized, replace
the steering knuckle.
Measurement range: Φ71-0.032 -0.062 mm
2. Press the front hub flange assembly.
On the press, press the front hub flange into the front hub
bearing mounting position using SST.
SST
SST

Downloaded from www.Manualslib.com manuals search engine GWFLORID Maintenance Manual116
3. Examine the front hub flange plate surface runout.
Examining methods are the same as the methods used
during disassembly. Plate surface runout should not exceed
0.03 mm.
4. Examine the front hub bearing assembly's starting
torque.
Examining methods are the same as the methods used during
disassembly. Put the SST on the wheel bolts which are at the
symmetrical locations. Put a dial torque wrench on the SST to
slowly rotate the flange's flange assembly (45°/4s), which re-
quires a starting torque range of 0.1-0.3 N·m
5. Install the snap ring for hole 72.
Use a bent nose retaining ring caliper for holes to install the
snap ring for hole 72 at the steering knuckle's retaining ring
mounting position.
6. Install the steering knuckle's front hub bearing and
front hub flange assembly.
7. Install the front brake disc cover.
Install the front brake disc cover on the steering knuckle, and
tighten the bolt to the set torque.
Tightening torque: 9±2 N·m
SST
8. Install the front brake disc.