Brake System: Hydro-Boost

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WARNING: Hydro-Boost unit should not be carried by accumulator. Do NOT drop Hydro-Boost on accumulator. Snap ring should be checked for proper seating before booster is used. Accumulator contains high-pressure nitrogen gas and can be dangerous if mishandled. Before disposing of boosters, drill a 1/16" (1.6 mm) hole in end of accumulator to relieve gas pressure.

The Hydro-Boost brake booster is a hydraulically operated brake booster powered by the power steering pump. See Figure. The power steering pump provides the fluid pressure to operate both the power brake booster and the power steering gear. A Hydro-Boost reserve system (accumulator) stores sufficient fluid under pressure to provide at least two power-assisted brake applications in the event the power steering pump fluid flow is interrupted. For low assist concerns on vehicles equipped with the Hydro-Boost system, see appropriate POWER STEERING SYSTEMS article in STEERING to check the power steering pump pressure and flow.

The brakes can also be applied manually if the reserve system is depleted. Model identification is stamped into the power brake booster housing near the power steering pressure hose. Any leakage goes directly back to the power steering pump reservoir.