10.2. Pumping of the hydraulic brake system
Pumping of a hydraulic actuator of brakes is necessary for removal of air which considerably reduces efficiency of braking. Air can get to a hydraulic actuator owing to depressurization of system at repair, replacement of separate knots or brake fluid.
Point the increased course of a pedal of a brake and its "softness" to availability of air in the drive. Before removal of air check tightness of all knots of the drive of brakes and their connections.
Carry out pumping of all system of the drive of brakes in the following sequence:
– right forward wheel;
– left forward wheel;
– right back wheel;
– left back wheel.
PERFORMANCE ORDER |
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1. Remove a dustproof cap from the union of pumping of the wheel cylinder, clear it and put on it a pure transparent hose which other end lower in the capacity which is partially filled with brake fluid. Capacity has to be at least 300 mm above the pumping union. Thanks to it hit of air in the cylinder through a pumping union carving is prevented. |
2. Sharply press a pedal of a brake of 3-5 times with an interval 2–3 sec., unscrew half way the pumping union at the pressed pedal. Continuing to press a pedal, force out the liquid which is in system together with air through a hose in capacity. |
3. After the pedal reaches extreme forward situation and the liquid effluence through a hose will stop, screw the pumping union to the full. Repeat these operations, the air outlet from a hose will not stop yet. |
4. Holding a pedal in the pressed situation, screw up the pumping union against the stop and remove a hose. |
5. Wipe the union of pumping and establish a protective cap. |
6. Repeat these operations for other wheels. |
Prevention
During removal of air constantly you monitor availability of brake fluid in a tank, without allowing an exposure of its bottom since at the same time air will get to system again.
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7. At absence the pedal has to pass about a half of the course in system of brakes of air. To exclude influence of the vacuum amplifier on pumping of brakes, you make removal of air at the idle engine. |
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