brake GREAT WALL SAFE 2006 Repair Manual

BR-23
Wheel-brake cylinder disassembly:
1. Tear down the dust cover steel gripping hoop and the
dust cover.
Tear down the dust cover steel gripping hoops and piston dust
covers of the four wheel-brake cylinders with the screwdriver.
2. Tear down the piston from the wheel-brake cylinder:
(a) Prepare a wooden block with the dimensions as shown in
the drawing (which is used to support the piston)
(b) Put the wooden block between the pistons and insert one
brake pad on one side of the wooden block.
(c) Tear down the four pistons from the wheel-brake cylin-
der by using the compressed air.
Warning: do not put your fingers in front of the piston
when using the compressed air.
3. Tear down the piston sealing ring.
Tear down the four piston sealing ring from the wheel-brake
cylinder with the screwdriver.
Check the front brake parts
1. Measure the thickness of brake pad liner;
Standard thickness
9.0mm
Min thickness
2.0mm
In case the liner is less than the min thickness or the liner is
worn unevenly, change the brake pad. Braking System
Front Brake(SF)
mm
mm
mm

BR-24
2. Measure the thickness of brake disc;
Standard thickness
20.0mm
Min thickness
18.0mm
If the brake pad is scraped, repair it; where the abrasion is
serious and its thickness is smaller than the min thickness,
change the brake disc.
3. Measure the bounding value of the brake disc face;
Remark: the bearing is required to be verified in the suitable
adjustment before measuring.
Max face bouncing value: 0.11mm;
4. Change the brake disc according to the requirement:
(a) Tear down the hub and the brake disc. (see the paragraph
of front wheel hub)
(b) Mount the new brake disc and screw up the connecting
bolts as the specified torque.
(c) Mount the hub and brake disc assembly. (see the para-
graph of front wheel hub).
Fastening torque
(75
5)N
m
(d) Mount the caliper bracket on the steering knuckle and
screw up the bolts according to the specified torque.
Fastening torque
123N
m.
Assembly of Brake-wheel pump
1. Preparation
All parts shall be washed, dried and cleared away the alien
materials, and coat moderate rubber lubricant on the work
faces of piston, piston dust cover and rectangular sealing ring.
2. Encase the piston sealing ring in the caliper body Braking System
Front Brake(SF)

BR-25
3. Encase the piston in the caliper body.
4. Encase the piston dust cover, dust cover steel-
gripping hoop in the caliper body.
Mount of Brake Calipers
1. Mount the brake caliper and screw up the two
mounting bolts.
Fastening torque
123N
m
2. Mount the brake pads;
3. Connecting the brake pipeline;
Use the open spanner to connect the pipeline.
Fastening torque
(21
1)N
m
4. Observe the height of brake liquid level and, if
necessary, add in the brake liquid and exhaust the air
in braking system.
Notice: avoid the brake liquid of spraying on the brake disc
when exhausting the air.
5. Check to see whether there is leakage of brake liquid. Braking System
Front Brake(SF)

BR-26
Rear brake
Element figure
wheel-brake cylinder cluster
pressure spring drag rod
self clearance-
adjusting bracing
wireparking brake arm
flat washer
split pinbrake shoe gear
return spring
parking brake push plate
push-plate spring back brake
shoe
self clearance-
adjusting toggle
tension spring
brake drum
clearance adjuster
pressure spring seatpressure spring front brake shoe
Disassembly of Rear drum-type Brake
Remark: if the braking torque of manual brake cannot satisfies
the braking requirement, it is suggested to check the thickness
of brake shoe liner, where the thickness is less than the min
thickness, change the brake shoe.
Min thickness
1.0mm
1. Tear down the rear wheel;
2. Tear down the brake drum;
Remark: in case the brake drum is not easy to tear down, the
following steps shall be adapted:
(a) Tear down the clearance-adjusting hole; insert a screw-
driver in the brake bottom plate hole to prize up the
adjusting bolt inner tilt angle with the self-adjusting fork.
(b) Use another screwdriver to adjust the adjusting bolt inner
tilt angle to loosen the clearance adjuster of brake shoe. DrBraking System
Rear Brake (Dr)

Parts that cannot be reused after being used

BR-27
3. Tear down the return springs of the two brake
shoes.
4. Tear down the self-adjusting bracing wire, brake shoe
retainer ring, bracing wire guide seat and the self-
clearance adjusting toggle plate.
(a) Press and push the self clearance-adjusting toggle plate to
teardown the bracing wire of self clearance-adjuster,
brake shoe retainer ring and bracing wire guide seat.
(b) Take out the spring from the self clearance-adjusting
toggle plate to tear down the clearance-adjusting toggle
plate and the spring.
5. Tear down the tension spring;
Tear down the tension spring with the pliers.
6. Tear down the brake shoe, clearance adjuster and
parking brake push plate.
(a) Tear down the pressure spring seat, pressure spring and
pressure spring drag rod.
(b) Tear down the brake shoe, clearance adjuster and parking
brake push plate.
(c) Tear down the bracing wire from the parking brake. Braking System
Rear Brake (Dr)

BR-28
7. Tear down the parking brake arm;
Tear down the split pin with pliers to take apart the parking
brake arm.
8. Take apart the brake pipeline from the wheel pump;
Tear down the brake pipeline and block the oil pipe with a clean
cork.
9. Tear down the wheel brake pump;
Tear down the two bolts and the wheel-brake cylinder.
10. Tear down the following bolts and wheel-brake
cylinder parts:
(a) Two piston rod;
(b) Two dust cover
(c) Two pistons
(d) Two piston rubber bows
(e) Spring. Braking System
Rear Brake (Dr)

BR-29
Check and Repair the Rear Brake Parts
1. Check and test the disassembled parts;
Check the disassembled parts to see whether there is abrasion,
rust or damage.
2. Measure the inner diameter of brake drum;
Standard inner diameter)
254.0mm
Mix inner diameter: 256.0mm
3. Measure the thickness of brake shoe liner;
Standard thickness
5.0mm
Min thickness
1.0mm
In case the thickness of brake shoe liner is less than the min
thickness or there is uneven abrasion, change the liner.
Remark: if one of the brake shoes is needed to change, all of the
brake shoes are required to change so that the even braking
performance is maintained.
4. Measure the brake liner and the brake drum to see
whether they contact closely;
If there is poor contact between the brake liner and the brake
drum, repair the brake shoe with the grinding devices, or
change the brake shoe cluster. Braking System
Rear Brake (Dr)

BR-30
Assembly of Rear Brake
remark: assemble the parts according to the
direction in the drawing;
left wheel
right wheel forward
1. Assemble the wheel-brake cylinder:
(a) Coat moderate lithium soap base glycol grease on the
piston cup;
(b) Assemble the wheel-brake cylinder:

Mount the two piston cups on two piston;

Encase the spring and two pistons in the wheel cylinder
body and

Mount the two dust covers
Remark: Assembly shall be conducted correctly according to
the direction shown in the drawing.
2. Mount the wheel-brake cylinder:
(a) Use two bolts to fix the wheel-brake cylinder on the rear
bottom plate.
Coat moderate sealing glue (Glue 704) on the position where
the wheel-brake cylinder connects with the bottom plate.
Fastening torque
(16
20)N
m
(c) Connect the brake pipeline on the wheel-brake cylinder.
Fastening torque
18N
m
3. Coat the following parts with moderate lubricant that
resistant high temperature (do not pollute the friction
plates);
(a) The upper plain of the hex convex platform where the
bottom plate connects the brake shoe;
(b) Contact face of the brake shoe and the top lever of wheel
cylinder;
(c) Contact face of the brake shoe with the support pin. Braking System
Rear Brake (DR)
Assembly of Rear Brake
forward

BR-31
(d) Adjusting bolts
(e) Contact position where the clearance adjuster and the
brake shoe.
4. Mount the parking brake drag arm;
Mount the new split pin with pliers to mount the parking brake
drag arm.
5. Mount the rear brake shoe:
(a) Mount the parking brake bracing wire on the parking
brake drag arm.
(b) Mount the rear brake shoe in such way that its end is
inserted into the cylinder rod. Encase the pressure spring
drag rod in the brake bottom plate and the brake shoe
assembly in turn and then insert it in the pressure seat ,
pressure spring, pressure spring seat, finally rotate the
pressure spring in place with the pressure spring fork.
6. Mount the parking brake pull plate and the front brake shoe:
(a) Mount the pull plate and the spring.
(b) Mount the front brake shoe, of which, the end is inserted
in the piston rod, and mount the pull plate. Insert the
pressure spring drag rod in the brake bottom plate and
brake shoe assembly in turn, then encase it in the pressure
spring seat, pressure spring and pressure spring, finally
rotate the pressure spring in place with the pressure
spring.
7. Mount the tension spring;
Mount the tension spring with pliers. Braking System
Rear Brake (DR)

BR-32
8. Mount on the adjuster;
Poke the brake shoes with the screwdriver and then mount the
adjuster.
9. Mount the brake shoe retainer ring, bracing wire of
guide seat, self clearance-adjusting bracing wire and
the return spring.
(a) Mount the brake shoe retainer ring, then the front return
spring.
(b) Mount the return spring ,and then mount the forward
return spring.
10. Mount the self-clearance toggle plate:
(a) Mount the toggle plate bracing wire torsion spring on the
rear brake shoe.
(b) Mount the clearance self-adjusting toggle plate and hook
It with the clearance-adjusting bracing wire.
(9) Hook the self clearance-adjusting toggle plate with the
bracing wire torsion spring
11. Check the operation of self-adjusting mechanism.
(a) Drag the clearance-adjusting bracing wire backward as
shown in the drawing, then release it. Check the clear-
ance-adjusting bolts to see whether it is rotating. If not,
check the rear brake to verify which part has problem.
(b) Adjust the clearance adjuster to shorten its length as
possible as can.
(c) Mount the brake drum
forward
Braking System
Rear Brake (DR)