Dongfeng DFA1101GZ5AD6J-907. Manual - part 52

Brake System

BR-4

Structure

Front brake

1.Pin, cotter
2.Front brake adjust arm assembly
3.Pin, cotter
4.Washer
5.Pin shaft--chamber push rod 
6.Hex bolt
7.Washer, spring
8.Washer, spring
9.Bolt
10.Front brake bracket assembly 
L. H.
11.Shim, adjusting
12.Front  brake chamber assembly 
L. H.

13.Hex bolt-to fix dust shield
14.Washer, spring
15.Plug-rear dust shield
16.Front dust shield
17.Front  brake plate L. H.
18.Screw
19.Wire, lock
20.Anchor pin-front brake
21.Rivet
22.Bushing-brake shoe
23.Front brake shoe
24.Return spring-rear brake shoe
25.Washer, spring
26.Hex bolt

27.Roller shoe-brake 

shoe
28.Roller 
29.Lock ring--brake shoe roller 
shaft
30.Pin shaft-Washer, spring
31.Front dust shield
32.Fitting, grease
33.Bush-brake plate
34.Seal washer,O type
35.Camshaft-front brake L. H.
36.Brake lining
37.Washer--brake cam
38.

Brake System

BR-5

Rear brake

1.Pin, cotter
2.Brake adjust arm
3.Pin, cotter
4.Washer
5.Fork,cotter
6.Pin,crew cut
7.Hex bolt
8.Rear spring accumulator 
chamber L. H.
9.Rear brake bracket assembly L. 
H.
10.Washer-camshaft
11.Hex bolt
12.Washer, spring

13.Rubber plug
14.Rear dustproof tray--rear 
brake 
15.Rear  brake plate
16.Screw--to fix brake shoe
17.Wire, lock
18.Shaft-shoe 
19.Rivet
20.Bush--rear brake shoe
21.Rear brake shoe
22.Return spring--rear brake shoe
23.Pin, return spring
24.Washer, spring

25.Screw--to fix brake plate
26.Roller shaft--rear brake shoe
27.Roller--rear brake shoe
28.Lock ring--brake shoe roller 
shaft
29.Rear dustproof tray--rear 
brake 
30.Fitting, grease
31.Bush-brake plate
32.Seal washer,O type
33.Cam-rear brake L. H.
34.Brake lining--rear brake shoe
35.Washer--brake cam

Brake System

BR-6

Front Brake

Disassembly

Remove the brake drum and wheel hub assembly, take down the return spring, brake shoe, brake cam, air chamber
bracket and brake bottom plate in sequence.

Check

1.Make sure whether the brake drum is damaged or distorted, replace in necessary.

2.When the brake drum is worn out and becomes out of round, it is allowed to bore, but the accumulative machin-

ing quantity should not exceed 4mm for the diameter direction.

3.When the brake drum assembly has been bored:

The run-out of the drum inside surface to the bearing axis (mm) <0.25

The difference of the inside diameters of left and right drums on one vehicle (mm) <1mm

4.The wear allowance of the lining thickness is 7mm. The distance from the lining surface to the rivet head should

not be less than 1mm. The lining surface should not be cracked and broken away. Otherwise, it should be
replaced.

5.The wear allowance of the shoe flat face at one end should not exceed 0.30mm.

6.Check carefully. There should not be any crack (especially at the two end hooks).

7.The diaphragm of the brake chamber should be in good condition. It should not have any ageing crazing or

crack. It is not allowed to use the same size diaphragms of different hardness on one truck.

8.Check clearance of all fitting surface.

Assembly

1.Install the assembled brake backing plate assembly on the front axle steering knuckle.

Tighten bolts with the specified torque                                   160~220N·m

2.Put the tightening bolts with the locking wires into the holes around the brake camshaft seat from the inside.

Install anchor pin into its seating holes and make two eccentric journals of the anchor pins opposite each other.

3.Assemble brake chamber brackets (with brake chamber assembly) in turn and tighten them. Put in the brake

camshaft and the adjusting washer. Then assemble the front brake slack adjuster on the brake camshaft and lock
it with the cotter pin. The brake air chamber push rod will be connected with the brake adjust arm by a pin.

4.Fit the brake shoes inside the brake backing plate. At anchor pin ends lock brake shoes with lock plate and cot-

ter pins.

5.The return spring is hooked between two brake shoes.

Brake System

BR-7

Adjust

After the brake linings have been replaced, the brake bot-
tom plates have been dismounted, causing the positions
of the anchor pins and the camshaft changed, the normal
contact of the brake linings and the brake drum is
destroyed; adjust the brake entirely as follows:

1.Take off the cover of the inspection hole on the drum.

Loosen the securing nuts of the anchor pins and the nuts of the securing nuts for the air chamber bracket.

2.Turn the anchor pins to make the marks at their ends opposite each other inwardly.

3.Turn the anchor pins and the worm shaft of the slack adjuster again and again to keep the linings fitted to the

drum fully. At the adjusted position, tighten the nuts of the air chamber bracket and the nuts of the anchor pins.
(Be careful to keep the positions of the anchor pin and the air chamber bracket fixed.)

4.Loosen the worm shaft 1/2~2/3 turn. The drum should rotate freely, but not touch the linings or any other parts.

The clearances between the brake linings and the drum should be:

Near the anchor pins                                             0.25~0.40mm

Near the camshaft                                               0.40~0.55mm

The difference of clearance at the same end of the two shoes                 ≤ 0.1mm

When braking linings worn out and the push rod stroke of the chamber exceeds 40mm, partial adjustment should
be done immediately to reduce the clearance between the linings and the drum. (Never turn the anchor pins to
destroy the good match of linings and drum.) When adjusting, face the worm shaft of slack adjusters, turn the
worm shaft clockwise, clearance decreased, and turn anticlockwise, clearance increased. It is wrong to adjust
clearance by tightening the push rod clevis for changing the stroke of push rod.

Note:
During adjusting the brake clearance, clean up dirt and filth on the head of the adjusting arm worm shaft.

Make use of a double offset ring spanner, cover it onto the worm shaft head, press the lock bush to release the
worm shaft and then turn the worn shaft. If the lock bush can't be pressed down, knock it with a hammer gently
and then press. After adjusting, cover with a rubber dust shield.

Lubricate

1.The brake cam surface

2.Camshaft journal

3.The anchor pins and the holes

4.Brake slack adjust arm assembly

5.Bearing holes of the camshafts on the brake chamber bracket