What's involved
What this repair actually is.
The booster is the power-assist unit between the pedal and the master cylinder — on most cars it uses engine vacuum to multiply your leg force. When the diaphragm fails, the pedal turns rock hard and stopping takes serious effort, often with a hissing sound. We replace the booster, reattach the master cylinder, bleed as needed, and road-test.
Symptoms
How you can tell.
- Brake pedal is suddenly very hard to press
- Hissing sound from under the dash when braking
- Car takes real effort to stop, especially at low speed
- Engine idle stumbles when you press the brake
- Braking assist fades after one or two pumps
If you delay
Without power assist your real-world stopping distance grows dramatically — most drivers can't press hard enough for an emergency stop.
Educational estimate. Real pricing depends on your vehicle, the inspection, parts availability, taxes, and shop rates. Use this as a guide while you shop quotes.
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