Part and system guide
Vacuum Hoses
Vacuum hoses carry engine vacuum to sensors, valves, and control devices.
What it does
Route intake manifold vacuum for fuel trim, emissions controls, brake assist on some vehicles, and actuator operation.
Failure signs
- Lean codes
- High idle
- Rough idle
- Hissing noise
- Stalling
Maintenance notes
- Inspect hoses for cracks, soft spots, collapsed sections, and disconnected ends.
- Smoke testing is useful for leaks that cannot be seen.
- Replace brittle hoses with correct vacuum-rated hose.