Kitten dual line braking system

Service Bulletin - January 1979............. number 1979/2


Dual line braking system

A dual line braking system has been introduced on all R.H.D. Kitten Saloon and Estate models from chassis number 8L14/14802982.

General Description

A dual line braking system is now used on all R.H.D. Kitten Saloon and Estate vehicles, operating drum brakes both front and rear. A tandem master cylinder and pressure reducing valve (PRV) are fitted for use with the dual line braking system.

The master cylinder incorporates a pressure failure switch, the purpose of which is to provide a visual warning of front or rear brake failure due to a loss of hydraulic pressure. Pressure generated in the master cylinder passes either side of a shuttle valve which under normal conditions remains stationary. Pressure failure in the front or rear brake hydraulic circuits causes the valve to move and actuate the switch, completing an electrical circuit to a warning light. on the vehicle fascia (see page 3). A test switch is incorporated in the system to check that both the bulb and the electrical system are operative.

The hydraulic system also incorporates a pressure reducing valve. This device reduces the hydraulic pressure to the rear brakes to prevent the rear wheels locking due to weight transfer during braking. In the event of front brake hydraulic failure the valve allows maximum pressure to operate the rear brakes to compensate for the loss in front wheel braking effect.

Master cylinder

To remove

1. Drain the system by attaching a bleed tube to the brake bleed valve. Unscrew valve one half turn and pump fluid into container by operating brake pedal. Discard used fluid.

2. From within the engine compartment prise out the blanking plug located on top of the drivers foot- well to gain access to the split pin, clevis pin and washer securing the brake master cylinder clevis to the brake pedal.

3. From inside the foot-well, remove the split pin and washer, withdraw the clevis pin and disconnect the master cylinder clevis from the brake pedal.

4. Disconnect the two hydraulic fluid pipes from the master cylinder ports and plug.

5. Disconnect the black/white harness leads from the pressure failure warning switch.

6. Unscrew the top nut and lock-washer securing the master cylinder and brake pedal mounting bracket to the body.

7. Remove the bottom socket bolt securing the master cylinder and pedal mounting bracket to the body.