Note. On models 1993 and 1994 issue the metering valve-regulator is built into the GTZ assembly.
1. On models since 1995 without anti-lock brakes (ABS), there are two metering valve regulators, both of which are screwed into the GTZ assembly. Models with ABS use a separately mounted control valve.
2. Valves-regulators are not subject to maintenance, and if the wheels begin to block prematurely during braking, the car should be driven away to be checked at a service station - a special pressure gauge will be required.
3. If the valve is leaking or otherwise damaged, loosen the union nut with a special split-head wrench, then unbolt the valve from the support bracket and unscrew it from the brake master cylinder assembly. After replacing the valve, bleed the brake system (see Section Bleeding the brake system).