Hard Brake Pedal Diagnosis - Ford F-150 2020
A consistently hard brake pedal indicates a loss of power brake assist, likely due to a vacuum or hydraulic issue in the brake booster system.
Diagnosis Details
Possible Causes
Failed brake booster vacuum hose or check valve - leak or blockage reduces vacuum assist.
Faulty brake booster diaphragm - internal leak prevents proper vacuum buildup.
Vacuum pump failure (if equipped) - insufficient vacuum supply for booster.
Related OBD-II Codes
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What You Should Do
Inspect the vacuum hose from the intake manifold to the brake booster for cracks, leaks, or disconnection.
Check the check valve operation.
Test the brake booster by pumping the pedal with engine off, then starting engine; pedal should drop slightly.
If not, replace booster or vacuum components as needed.
Related Repairs
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Disclaimer: This AI-generated diagnosis is for informational reference only. Always consult a qualified mechanic for an in-person inspection. AutOwner is not responsible for decisions made based on this information.