Volkswagen Golf/Jetta 2 manual

General information and precautions
Braking system / General information and precautions

General information
The braking system is of hydraulic, dual circuit type with discs at the front and drum or discs at the rear. The hydraulic circuit is split diagonally so that with the failure of one circuit, one front and one rear brake remain operative.

A load-sensitive pressure regulator is incorporated in the rear hydraulic circuits on some models to prevent the rear wheels locking in advance of the front wheels during heavy application of the brakes. The regulator proportions the hydraulic pressure between the front and rear brakes according to the load being carried and is located on the under-body, in front of the left-hand rear wheel.

A vacuum servo unit is located between the brake pedal and master cylinder. It provides assistance to the driver when the brake pedal is depressed. The unit operates by vacuum from the inlet manifold and comprises diaphragm and non-return valve. With the brake pedal released, vacuum is channelled to both sides of the diaphragm. With the pedal depressed, one side is opened to atmosphere. The resultant unequal pressures are harnessed to assist in depressing the master cylinder pistons.

The handbrake operates on the rear wheels only, its lever incorporating a switch which illuminates a warning light on the instrument panel when the handbrake is applied. The same warning light is wired into the low hydraulic fluid switch circuit.

Hydraulic fluid is poisonous. Wash off immediately and thoroughly in the case of skin contact and seek immediate medical advice if any fluid is swallowed or gets into the eyes.

Certain types of hydraulic fluid are inflammable and may ignite when allowed into contact with hot components. When servicing any hydraulic system, it is safest to assume that the fluid is inflammable and to take precautions against the risk of fire as though it is petrol that is being handled.

Hydraulic fluid is an effective paint stripper and will attack plastics. If any is spilt, it should be washed off immediately using copious quantities of fresh water. Finally, it is hygroscopic, that is it absorbs moisture from the air. Old fluid may be contaminated and unfit for further use.

When topping-up or renewing fluid, always use the recommended type and ensure that it comes from a freshly-opened sealed container.

When working on the brake components, take care not to disperse brake dust into the air, or to inhale it, since it may contain asbestos which is injurious to health When servicing any part of the system, work carefully and methodically. Observe scrupulous cleanliness when overhauling any part of the system. Always renew components (in axle sets, where applicable) if in doubt about their condition and use only genuine VW replacement parts, or at least those of known good quality.

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