12.2. Prorolling of hydraulic brake system

THE GENERAL DATA

Arrangement of the union of prorolling on a forward support

The prorolling union is specified by an arrow.

Arrangement of the union of prorolling on the back working brake cylinder

The prorolling union is specified by an arrow.

Prorolling of a hydrodrive of brakes is necessary for removal of air which considerably reduces efficiency of braking. Air can get to a hydrodrive owing to system depressurization at repair, replacement of separate knots or a brake liquid. In air presence in a drive specify the increased course of a pedal of a brake and its "softness".

At absence in system of brakes of air, the pedal should pass about half of course. To exclude influence of the vacuum amplifier on prorolling of brakes, air removal to make at the idle engine.

PERFORMANCE ORDER

1. Before air removal to check up tightness of all knots of a drive of brakes and their connections. 2. To remove a dustproof cap from the union of prorolling of the wheel cylinder, to clear it and to dress on it the pure transparent hose which other end to lower in the capacity partially filled with a brake liquid. The capacity should be at least on 300 mm above the prorolling union. Thanks to it air hit in the cylinder through a carving of the union of prorolling is prevented. 3. Sharply to press a pedal of a brake of 3-5 times with an interval 2–3 seconds, to unscrew on a half-turn the prorolling union at the pressed pedal. 4. Continuing to press a pedal, to supersede a liquid being in system together with air through a hose in capacity. 5. After the pedal will reach extreme forward position, and вытекание liquids through a hose will stop, to screw the prorolling union home. 6. To repeat these operations the air outlet from a hose will not stop yet. 7. Keeping a pedal in the pressed position, to screw up the prorolling union against the stop and to remove a hose. 8. To wipe the union of prorolling and to establish a protective cap. 9. To repeat these operations for other wheels. The prevention At air removal constantly to watch presence of a brake liquid in a tank, without supposing an exposure of its bottom since thus air again will get to system.

Sequence of prorolling

USUAL BRAKE SYSTEM

1) the Right back wheel.
2) the Left forward wheel.
3) the Left back wheel.
4) the Right forward wheel.

SYSTEM BENDIX WITH ABS

Detachment of a three-contact socket at prorolling of system Bendix with ABS

Before prorolling performance to switch off ignition and to disconnect a brown three-contact socket from hydraulic assemblage of the modulator.

Arrangement on the hydraulic modulator of the basic and additional union of prorolling of system Bendix with ABS

1 – the basic union of prorolling, 2 – the additional union of prorolling

1) the Back brake, the most remote from the main cylinder.
2) the Back brake closest to the main cylinder.
3) the Forward brake, the most remote from the main cylinder.
4) the Forward brake closest to the main cylinder.
5) the Hydraulic modulator.

SYSTEM BOSCH C ABS

1) the Left forward wheel.
2) the Right forward wheel.
3) the Left back wheel.
4) the Right back wheel.

If there are difficulties at prorolling of hydraulic system Bosch with ABS, to execute prorolling in a following order:

1) the Right back brake.
2) the Left back brake.
3) the Left forward brake.
4) the Right forward brake.