Remove/install brake shoes

AR42.10-B-1020D

Remove/install brake shoes

04.08.2020

Model

688.1 with rear axle 743.4

Modification notes

03.12.2019

Parafuso de fixação do regulador de folga

BA42.10-B-1003-16A

1

Brake plate

11

Top winding spring

2

Wheel brake cylinder

12

Clamping shank

3

Primary shoe

13

Spring plate

4

Secondary shoe

14

Retaining spring

5

Brake lining

15

Lever

6

Governor

16

Pins

7

Lower winding spring

17

Pressure bar

8

Diagonal winding spring

18

Parking brake lever

9

Diagonal winding spring

19

Screws

10

Top winding spring

20

Parking brake lever

Topical note

Notes on repairs to brake system

.

AH42.00-P-0003-01A

 

Remove/install

1

Place the vehicle on an appropriate place, preferably a level place, that allows working safely.

2

Slightly loosen the wheel nuts without removing them.

 Danger

Risk of death caused by improper lifting of cab. Risk of injury caused by body parts being trapped and crushed when lowering cab

Only used approved lifting cradles. Ensure that the mounts are securely seated. Stay out from underneath a hanging cab..

AS60.80-Z-0002-01A

3

Lift the vehicle

 Support the vehicle on trestles conveniently arranged under the chassis, on both sides, so as to enable removing the wheels and work on the brakes in a safe manner.

4

Remove the wheels

.

AR40.10-B-1100F

5

Remove the brake drum

.

AR35.20-B-0310C

6

Check the brake linings for wear

 Whenever it is necessary to replace the linings, the complete set of linings must be replaced.

 Before removing the brake shoes, mark them conveniently by identifying their assembly position so that, upon installation, they are mounted at the same position.

Brake linings should be replaced whenever they show the following conditions:



Reach the minimum allowable thickness and indicated by the wear sensors;

Show uneven wearing;

If the linings are contaminated with oil, grease or brake fluid.

7

Disconnect the wear sensors from the brake shoes

 Vehicles equipped with brake linings wear indicator.

8

Release the diagonal winding springs (8) and (9)

9

Release the top and bottom winding springs (7), (10) and (11)

10

Remove the elastic fastener from the primary and secondary brake shoes (3) and (4)

 Remove the retaining spring (14), the spring retainer (13), and move back the clamping shank (12).

11

Remove the primary and secondary brake shoes (3) and (4)

12

Remove the elastic fastener from the parking brake lever (18)

 Remove the retaining spring (14), the spring retainer (13), and move back the clamping shank (12).

13

Extract the pin (16) from the parking brake lever (18) and the parking brake lever (18)

 Release the pin retaining ring (16) and remove it.

14

Uncouple the lever (18) of the parking brake cable (20) and remove the lever

15

Remove from the lever (15) the pin retaining ring (16) and remove the pressure bar (17)

16

Remove the fastening screws (19) from the parking brake cable (20) and remove the brake plate (1) cable

 .Bolt that fastens the traction cable to the brake supports plate

*BA42.20-B-1005-01A

17

If the governor (6) shows any fault, remove it


Do not release the governor screws if removing these is unnecessary.
Since the governor is fixed by microencapsulated screws, loosening the threads on the regulator can be damaged.
In case of removal of the governor, check the condition of the thread before reinstalling it.

 Installation: For the assembly of the governor, it is necessary to use either new microencapsulated screws or chemical lock.

Auto Lock

*BR00.45-Z-1115-01A

 .Fastening bolt of the clearance regulator

*BA42.10-B-1003-16A

18

Symmetrically adjust the governor (6)

.Automatic adjuster expansion measurement

*BE42.15-B-1001-01B



Check

Topical note

Guidelines for cleaning brake linings

AH42.10-N-0005-01A

19

Inspect whether all the brake parts are in perfect condition

20

Inspect the contact surfaces of the primary and secondary shoes (3) and (4) and the brake retainer (1)

 Installation: Appropriate sliding of the shoes on the brake retainer should be ensured (1).

 Lubricate all the brake shoe mechanism contact points.

Molykote paste HTP special lubricating grease

*BR00.45-Z-1028-06A

21

Install in reverse order

Values for attesting the mechanical aspects

Number

Designation

Type 688.1 with drum brake rear axle

BE42.15-B-1001-01B

Automatic adjuster expansion measurement

Measure A

Perrot device

mm

86,0

MB device

mm

0,4...0,6

Measurement B

Perrot device

mm

85,0

MB device

mm

12,5

 Drum brake

Number

Designation

Type 688.1 (except 688.156)

BA42.10-B-1003-16A

Fastening bolt of the clearance regulator

Nm

45...50

 Parking brake

Number

Designation

Type 688.1

BA42.20-B-1005-01A

Bolt that fastens the traction cable to the brake supports plate

Nm

20...25

Repair materials

Number

Designation

Order number

BR00.45-Z-1028-06A

Molykote paste HTP special lubricating grease

Use corresponding commercially available repair materials.

BR00.45-Z-1115-01A

Auto Lock

Loctite 271