HIGH RISK
Common symptoms
- See page for quick checks
Cost expectations
Typical costs vary by car and region. Use this as a ballpark.
- DIY / parts: £20–£80
- Garage / labour: £80–£250
Most likely causes (ranked)
Start at the top. Rule out the common, cheap causes before expensive ones.
- Air in brake lines
- Brake fluid leak
- Worn pads/low fluid
- Failed master cylinder
- Flexible hose swelling
Quick checks (fast, low-cost)
Fast checks you can do with basic tools before buying parts.
- Check brake fluid level.
- Inspect for leaks at calipers/lines.
- If pedal improves when pumped, suspect air/leak.
- Do not drive if braking is compromised.
- Bleed system properly after repairs.
Recommended tools
These tools make diagnosis faster and stop you buying random parts.
Related fixes
If your symptoms don’t match perfectly, check these next.
What to do next
- Fix leaks before bleeding.
- If pedal still sinks, test master cylinder.