Note: Before starting work, refer to the warning at the beginning of Section 2 concerning the dangers of hydraulic fluid.

1.6 GTI models
General information
1 On 1.6 GTI models the brake hydraulic circuit is split front-to-rear, and an inertia type compensator is incorporated in the rear brake circuit to prevent rear wheel lock-up during hard braking. The compensator is located in the engine compartment on the lower left-hand side panel (see illustration),

13.1 Rear brake compensator fitted to 1.6 GTI models

and incorporates a steel ball which stops fluid entry to the rear circuit at a preset deceleration.

Removal
2 To minimise fluid loss, unscrew the master cylinder reservoir filler cap and place a piece of polythene over the filler neck. Secure the polythene with an elastic band ensuring that an airtight seal is obtained.

3 Chock the rear wheels then jack up the front of the car and support it on axle stands (see “Jacking and vehicle support”). Remove the relevant front roadwheel.

4 Unscrew the union nuts and disconnect the rigid hydraulic lines from each end of the unit while holding the unit on the flats provided.

5 Unbolt the clamp and withdraw the compensator.

Refitting
6 Refitting is a reversal of removal, but note that the nose of the unit must face forwards and be inclined upwards at an angle of 22° to the horizontal. Provided that the mounting bracket is undamaged, this angle will automatically be achieved. Finally bleed the rear hydraulic circuit, as described in Section 2.

1.9 GTI models
General information
7 On 1.9 GTI models, the hydraulic circuit is split diagonally and two compensators are fitted. Each compensator is located in the rear circuit near the rear wheel (see illustration).

13.7 Rear brake compensator fitted to 1.9 GTI models

They are of fixed calibration, and not load-sensitive.

Removal
8 To minimise fluid loss, unscrew the master cylinder reservoir filler cap and place a piece of polythene over the filler neck. Secure the polythene with an elastic band ensuring that an airtight seal is obtained.

9 Chock the front wheels then jack up the rear of the car and support it on axle stands (see “Jacking and vehicle support”).

10 Unscrew the union nuts and disconnect the rigid hydraulic lines from each end of the unit while holding the unit on the flats provided. Ease out the pipes and remove the compensator from under the car.

11 Note that from December 1988, modified compensators have been fitted. The modified components can be identified by the letter on the compensator body. Early components have the identifying letter “F”, while later components have the identifying letter “E”.

The later components can be used to replace the early components, but both compensators must be of the same type.

Refitting
12 Refitting is a reversal of removal. Bleed the relevant hydraulic circuit, as described in Section 2 on completion.