ABS Powermaster III

The Powermaster III is a booster/modulator designed to provide base (normal) and anti-lock braking power. Fluid pressure is created and maintained by a combination of an electric motor/pump and accumulator. The accumulator is pre-charged to 1200 psi and the electric pump maintains system pressure at 2700 psi. During anti-lock braking, the fluid pressure is modulated by three solenoid assemblies. One assembly for each front wheel and one assembly for the rear brakes. Each solenoid assembly can apply, hold, or release pressure in the line it controls. Each front wheel can be modulated separately (first one, then the other), but the rear brakes have to be modulated together. This system is commonly called a Select-Low 3-Channel System. The Powermaster III is located in the left rear corner of engine compartment.