Brakes
Master Cylinder
The master cylinder converts pedal force into hydraulic pressure for all four brakes.
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Brake system flow
Interactive — tap a partTap a part to see how it fits in the system.
What it does
- Pressurizes the brake fluid when the pedal is pressed
- Feeds the calipers and wheel cylinders
- Works with the brake booster
When it fails
- Low or spongy brake pedal
- Pedal slowly sinks to the floor
- Brake warning light
- Fluid loss with no visible leak
How to diagnose
- Check the fluid level and condition
- Pump the pedal with the engine off to test the booster
- Bleed the brakes to remove air
- Pressure-test the system
Maintenance
- Flush the fluid on schedule (moisture ruins brakes)
- Never mix DOT 3/4 with DOT 5 (silicone)
Use the diagnosis order. When a part fails, confirm each hypothesis with measurements before replacing anything — codes and symptoms overlap.