Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Power Brake Units - BENDIX Single Diaphragm: Description
CHANGES, CAUTIONS, CORRECTIONS
FORD MOTOR CO. "CLUNK" NOISE: A "clunk" noise may be experienced upon brake application (due to clearance between power unit push rod and master cylinder piston). Separate master cylinder from power unit and adjust push rod screw outward 1/2 turn. Reassemble master cylinder to power unit. Ensure master cylinder compensation port has not been blocked: With engine running, quick brake application should produce fluid motion in front reservoir. If no motion is observed, adjust push rod screw inward 1/4 turn.
Vacuum suspended, self-contained, vacuum-hydraulic unit which utilizes engine manifold vacuum and atmospheric pressure to provide its power. Vacuum power unit contains power piston assembly, which houses control valve, reaction mechanism, and return spring. Control valve consists of air valve, floating control valve assembly, and push rod. Reaction mechanism consists of reaction plate and levers. A vacuum check valve is mounted in front housing for connection to vacuum source.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.