LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Land Rover >> 1987 >> Range Rover >> Repair and Diagnosis >> Engine Performance >> System >> Emission Control System >> Testing >> Vacuum Delay Valve >> Check Valve Air Flow
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Check Valve Air Flow

  1. Attach a 10 cubic inch vacuum tank to coloured side of valve.
  2. Expose black side to atmospheric pressure.
  3. Expected result of time required for vacuum to drop from minus 20" Hg to minus 2" Hg should be .5 second maximum.
  4. To check vacuum recovery air flow attach a 23 cubic inch vacuum tank to black side of valve.
  5. Expose coloured side to atmospheric pressure.
  6. Expected result time required for vacuum to drop from 16" Hg to 8" Hg will be 4-6 minutes.