Chery A15. Manual - part 211

   

 

Figure: Structure of Rear Wheel Drum Brake 

1-Brake back plate   2-Pin roll   3-Retracting spring   4-Brake shoe positioning spring    

5-Push rod   6-Parking brake arm drag      7-Brake shoe and arm drag assembly   8-Bracket   

9-Support plate   10-Rivet   11-Lower retracing spring   12-Tension spring   13-Check hole 

14-Pressure spring   15-Clamp pin   16-Spring seat 

17-Brake shoe and toothed wedge regulating plate assembly      18-Friction lining 

19-Wedge regulating plate   20-Wedge regulating block   21-Brake wheel cylinder 

 

1. Structure of Rear Wheel Drum Brake 

Brake back plate 1 is fastened on rear axle flange end. Brake wheel cylinder 21 is 

fixed on back plate, and bracket 8 and support plate 9 are fixed under back plate with 

rivet 10. The upper end of brake shoe ventral shield is supported in the slots on both 

sides of wheel cylinder, and the lower end is borne by support plate 9. Clamp pin 15, 

spring seat 16 and pressure spring 14 together press the brake shoe onto the bearing 

plane of brake back plate to avoid axial displacement of brake shoe. Float bearing of 

brake shoe allows it to float a little along brake wheel cylinder piston plane and 

bearing plane of support plate, and the self-centering function of brake shoe ensures 

the full face contact of brake shoe and brake drum. Wedge regulating plate 19 on 

brake shoe and toothed wedge regulating plate assembly works with wedge regulating 

block to adjust clearance between shoe and brake drum. Parking brake arm drag 6 is 

able to swing around pin roll 2. The small hook slot in the lower part of parking brake 

arm drag 6 is used to hook the end of parking brake dragline. Friction lining 18 is 

riveted on the working surface of brake shoe. Lower ends of both brake shoes are 

tightened by lower retracing spring 11, and upper ends are tighten by brake shoe 

positioning spring 4 and secondary retracing spring 3. 

2. Operation of Rear Wheel Drum Brake 

When braking, brake wheel cylinder piston pushes brake shoe by the force of brake 

fluid to rotate it outward around the contact point of brake shoe and support plate, 

thus pressing the friction disk of brake shoe onto brake drum to produce brake torque 

and finally achieve vehicle braking. 

When the brake is released, brake shoes return to their original positions with the help 

of retracting spring 3, 4 and 11 after the brake pressure disappears. 

   

 

Braking clearance of rear brake is self-regulated. In case the braking clearance 

exceeds set value due to shoe plate wear, wedge regulating block 20 located between 

lever and brake shoe will be pulled down by tension spring 12 to compensate the 

increased clearance between lever and wedge regulating block, and brake shoe will be 

opened wider toward brake drum to compensate worn part of friction disk. 

 

IV. Parking Brake 

Parking brake is realized by adding a hand operating control mechanism on rear 

wheel brake. As shown in the figure below, parking brake shares the same brake with 

rear wheel brake, thus simplifying the structure and reducing the weight. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

1. Brake handle   2. Drawbar   3. Adjusting nut    
4. Locknut (8Nm)   5. Compensation rod   6. Nut (20Nm)    
7. Parking brake dragline      8. Parking brake dust cover assembly 

Installation and adjustment of parking brake system (as shown in the figure above) 

Fit tightly the dust cover assembly on parking brake control mechanism, and lock the 

mechanism assembly onto the welded screw on vehicle body, tightening torque is      . 

(only applicable to BMW engines) 

   

 

1. Parking brake dragline is connected to compensation rod through hand brake sleeve 

(fixed on vehicle body) and parking brake dragline conduit, and then fixed on bottom 

of vehicle body by bracket clamp, brake line lock thread and dragline hanger 

assembled on rear axle. 

2. Connect parking brake dragline and compensation rod with adjusting nut and 

locknut, tightening torque is 9±3Nm. 

3. Fix the drawbar of parking brake control mechanism assembly to compensation rod, 

and then turn it 90º to fix it on vehicle body. 

4. Parking brake controls rear wheel brake through the dragline. 

 

V. Vacuum Booster and Brake Master Cylinder 

A15 series adopt 228.6mm (9in) vacuum booster and tandem type brake master 

cylinder for brake assistance, which is realized by vacuum produced by working 

engine. Vacuum chamber of the booster is connected with air intake pipe of engine 

through vacuum tube and check valve. 

Tandem type brake master cylinder consists of cylinder body, piston, spring, spring 

seat, rubber cap, etc. Brake master cylinder is connected with fore end of booster by 

two bolts. A brake fluid tank is fixed on brake master cylinder, which includes two 

serial working chambers (primary chamber and secondary chamber). 

Main technical parameters of A15 car brake system: 

Brake master cylinder: φ22.2mm 

Vacuum booster: Φ228.6mm（9in） 

Vacuum booster boost ratio: 3.9:1 

Primary chamber travel: 16 mm 

Secondary chamber travel: 18 mm 

Front wheel disk brake: wheel cylinder diameter: Φ54mm 

Brake disk outer diameter: Φ256mm 

Brake disk thickness: 13mm 

Front friction shoe thickness: 14mm 

Rear drum brake: brake drum diameter: Φ200mm 

   

 

Rear drum brake wheel cylinder diameter: Φ17.46mm 

Rear drum brake shoe plate: Φ200mm×40mm×5mm 

Brake power distribution ratio: front wheel 65%, rear wheel 35% 

Parking brake: acting force of parking brake control handle (38mm from end) < 

400N with 20% full load on ramp 

 

 

Section Two: Maintenance of Brake System 

 

I. Disassembly/Assembly and Inspection of Front Wheel Disk Brake 

(I). Disassembling/Assembling Disk Brake 

1. Disassemble Steps 

(1). Lift the car and demount front wheel. 

(2). Loosen and remove tightening bolt (where   

the arrow points) 

(3). Take off brake caliper shell and brake shoes. 

2. Assemble Steps 

Assemble sequence is reversed from disassemble 

sequence. Attention shall be paid to the following: 

(1). Brake shoe with a larger friction surface shall 

be installed outside. 

(2). Brake shoes on both sides shall be replaced at   

the same time, and replacing ones shall be   

manufactured by the same one supplier. 

(3). Tightening torque of fastening bolt is 25Nm 

(as shown in the figure) 

 

(4). Tightening torque of wheel bolt is 110Nm.