2.15. Check of the brake system
The following signs can testify to malfunction in the brake system:
– the car pulls aside when pressing a brake pedal;
– the scratch of brakes is heard;
– excessively free wheeling of a pedal of a brake;
– brake pedal pulsation;
– leak of brake fluid, etc.
Disk brakes
| PERFORMANCE ORDER |
|
1. Check thickness of brake slips through an opening in a support (are specified by shooters). |
| 2. For exact check of thickness of brake slips and their state remove supports of brakes and brake slips. Clear slips and check thickness and a condition of frictional material. |
| 3. Measure thickness of a brake disk by means of a micrometer. Examine a disk surface on existence of deep scratches or flutes. |
| 4. Check all brake tubes and hoses for existence of damages or wear. Check reliability of fastenings and connections. |
|
Back drum brakes
| PERFORMANCE ORDER |
|
1. To check thickness of frictional material of brake shoes, without removing the brake drum, remove a rubber cap (it is specified by an arrow) and examine blocks. |
| 2. For more careful check turn off two fixing screws in the center of the brake drum and remove a drum. |
| 3. Clear the brake mechanism by means of means for cleaning of brakes. |
|
4. Measure thickness of frictional material of brake shoes. If material height over heads of rivets is less than 1,5 mm, blocks need to be replaced. |
|
5. Check a condition of springs of the mechanism of a brake. Examine the wheel cylinder on existence of traces of leak. Check integrity of covers of the cylinder. Check brake tubes and connections. |
| 6. Examine the internal surface of the brake drum on existence of cracks, deep scratches and wear tracks. |
|
Vacuum amplifier of the brake system
| PERFORMANCE ORDER |
| 1. Squeeze out a pedal of a brake and start the engine – the pedal has to fall a little. |
| 2. At the working engine squeeze out a brake pedal several times – the course of a pedal of a brake should not change. |
| 3. Squeeze out a brake pedal, kill the engine and hold a pedal in the pressed state within 30 seconds – the pedal should not fall. |
| 4. Start the engine, let's it work several minutes and kill the engine. Squeeze out a brake pedal several times – the course of a pedal has to decrease with each pressing. |
| 5. If the pedal of a brake behaved differently, the vacuum amplifier means it is faulty, and it needs to be replaced. |
|
Emergency brake
| PERFORMANCE ORDER |
| 1. Count number of the clicks necessary for reliable statement of the car on the emergency brake. Adjust the mechanism of the emergency brake if it is necessary. |
| 2. Check that the emergency brake could hold the car on a steep slope. |
| 3. Squeeze out a brake pedal, kill the engine and hold a pedal in the pressed state within 30 seconds – the pedal should not fall. |
| 4. Start the engine, let's it work several minutes and kill the engine. Squeeze out a brake pedal several times – the course of a pedal has to decrease with each pressing. |
| 5. If the pedal of a brake behaved differently, the vacuum amplifier means it is faulty, and it needs to be replaced. |
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