Hard Brake Pedal Diagnosis - Toyota RAV4 2020
A consistently hard brake pedal indicates a loss of power brake assist, likely due to a failed vacuum booster, a vacuum leak, or a faulty brake booster check valve. This reduces braking effectiveness and increases stopping distance.
Diagnosis Details
Possible Causes
Failed brake booster (vacuum assist unit) - internal diaphragm leak or mechanical failure
Vacuum leak at the booster hose, check valve, or intake manifold connection
Faulty brake booster check valve allowing vacuum loss
Related OBD-II Codes
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What You Should Do
Inspect the brake booster vacuum hose and check valve for cracks or disconnection.
Test the check valve by blowing through it (should only flow one way).
If the hose and valve are intact, the booster itself is likely faulty and needs replacement.
Do not drive the vehicle until repaired.
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.