LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Ford >> 1984 >> Bronco II Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Vacuum Delay Valves >> Testing
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Vacuum Delay Valves: Testing

  1. Connect hand vacuum pump and hose to valve to be tested. Valves with both sides the same color are good, if vacuum can be built up in both directions before bleeding off.
  2. Valves with one side Black or White and the other side colored are good if vacuum can be built up in one direction only before bleeding off.
NOTE: Use care to prevent oil or dirt from entering valves during testing.
Fig 1: Four Types of Vacuum Delay Valves Valves can best be tested with vacuum pump.
G8784