This procedure does not apply if the model is equipped with an Anti lock Braking System (ABS). First of all, unscrew the wire connector from the pressure differential switch , pay attention to the side lock releases that must be squeezed before the connector is pulled up , a pair of pliers could be useful at this step. Remove a thin wire and connect it with another good wire to the ground terminal and turn the ignition key to On position to see if the lamp blinks in the instrument cluster. If it does not light up then either the lighting bulb is damaged and needs to be replaced or there is a problem with the electrical circuit governing its operation. Once warning light operates, there is need to switch off the car's ignition, reconnect the wire to the right terminal and refill the master cylinder reservoirs. Connect a bleeder hose to one of the rear wheels' bleeder valves though the other end should be placed in a container with fresh brake fluid and then start the car's ignition. Lift the lid of the bleeder valve while another person depresses moderately the brake pedal and this will lead to the glow of the brake warning light. Unscrew the bleeder valve when the helper lets off the brake pedal and twist it back to snuff out the warning light. Perform this process to one of the front brake bleeder valves. If the warning light fails to come on but come on when jumper connected to ground it indicates that the warning light switch part of the combination valve has failed and requires the substitution of the combination valve because all parts of it are not separable for service. For replacement, stand a container under the combination valve with painted surface covered with newspapers or rags. Remove the hydraulic lines from the combination valve using a flare-nut wrench, and cap the lines so that the fluid cannot get out and mix with other fluids. Remove the battery connector of the pressure differential switch, the bolt of the valve to the bracket, and the valve out of the car. Removal is the reverse of installation and after installation the whole braking mechanism has to be flushed.
