Brake Booster - Hydro-Max

The Hydro-Max power brake system is composed of a hydraulic-powered booster, a mini master cylinder, a reserve system electric motor pump, a relay, an electric monitor and an integral pressure differential switch.

Fig 1: Identifying Hydro-Max Power Brake System Components

Courtesy of FORD MOTOR CO.

NOTE: The Hydro-Boost power brake booster is generally self-bleeding, and the following procedure will normally bleed the air from the power brake booster. Normal operation of the vehicle will further remove any additional trapped air.

Fill the power steering oil reservoir with clean automatic transmission fluid.
Remove the powertrain control module (PCM) relay to prevent the engine from starting.

Fig 2: Removing Powertrain Control Module Relay
Courtesy of FORD MOTOR CO.
Crank the engine for several seconds.
Check the fluid level in the power steering oil reservoir, and add if necessary. Install the powertrain control module (PCM) relay.

Fig 3: Installing Powertrain Control Module Relay
Courtesy of FORD MOTOR CO.
Start the engine.
With the engine running, turn the steering wheel from stop-to-stop twice. Turn the engine off.
Depress the brake pedal several times to discharge the accumulator.
Repeat Steps 5 and 6 .
If foaming occurs, stop the engine and allow the foam to dissipate.
Repeat Steps 5 and 6 as required, until all the air is removed from the system and the foaming stops.