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Removal of air from hydraulic system
Bleeding the brakes is necessary for removal of air from the hydraulic circuit, which greatly reduces the effectiveness of the service braking system. Air can get into the hydraulic system depressurization due to the repair or replacement of individual units, and replace the brake fluid. The presence of air in the brake actuator indicates increased brake pedal travel and its "softness". Priming need new brake fluid. The company ?�Volkswagen?� recommends a brake fluid grade SAE J 1703 DOT 3. Before removing the air from the brake system check the tightness of all knots of a drive of brakes and their connections, clean the cover and the area around the reservoir cap thoroughly clean the bleed screw. Bleeding brake system is necessary after each repair brake system, if the opening drive of the hydraulic system of brakes.
A WARNING On models with ABS fittings to remove air from the hydraulic modulator can not turn away under any circumstances. |
If there was only a part of the system depressurised and thus has complied with all the precautions necessary to minimize the loss of fluid, the air must be removed only in this part of the system (ie, the first or second path). If it is necessary to remove air from the entire system, it must be performed in the following order: - Right rear brake; - Left rear brake; - Right front brake; - Left front brake.
NOTE During pumping constantly watch levels of brake fluid and keep it at the level of "Max." |
A WARNING It is impossible to apply the liquid discharged from the system for filling the tank, as it is filled with air, has a lot of moisture and possibly contaminated. |
Pumping the brake sequence is as follows: - Remove the dust cap from the first order of fitting, clean the bleed screw and put on it a hose to drain the liquid, and its free end in the lower glass container partially filled with brake fluid; - Ask the assistant several times sharply depress the brake pedal until it appears sharp counteraction to raise the pressure, and then hold down the pedal; - Unscrew by 1/2 - 3/4 turn fitting when the pedal is depressed. Continuing to press the brake pedal, supersede a liquid being in system together with air through a hose into the vessel. Brake pedal "will go" into the floor, hold it in this position, tighten the bleeder valve;
NOTE Make sure that the hose end is continuously immersed in the liquid. |
- Repeat this operation as long as no air bubbles in the air from the hose; - Top up the brake fluid in the reservoir, maintaining the level near the mark "Max"; - Holding the brake pedal down, tighten the fitting to the full, remove the hose and put the cap; - Repeat steps for the other brake until the system will not be removed all the air, and the brake pedal does not become "rigid"; - If the brake pedal is pressed the feeling of its "softness", the system is still the air and you want to continue removing it. The inability to remove the air, despite repeated attempts, it may be related to the deterioration of the seals of the master cylinder; - Check the rubber seal tank; - After pumping refill the brake fluid in the reservoir up to the mark "MAX"; - Check the tightness of all the system connections; - Make a test drive, during which caution.
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