LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Ford >> 1989 >> Bronco II RWD, Standard, M5OD-R1 >> Repair and Diagnosis >> Engine Performance >> System >> Air Injection System >> Diagnosis >> Combination Air By-Pass/Air Control Valve
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Combination Air By-Pass/Air Control Valve

  1. Disconnect air supply hoses from outlets "A" and "B". See Figure . Disconnect and plug vacuum line to vacuum port "D". Raise engine speed to 1500 RPM. Air supply should exit out by-pass vents.
  2. Reconnect vacuum line to vacuum port "D". Disconnect and plug vacuum line at port "S". With engine at idle, ensure vacuum is present in vacuum hose to port "D". Raise engine speed to 1500 RPM. Air supply should exit outlet "B" and no air should be detected at outlet "A". See Figure .
  3. Apply 8-10 in. Hg (27-34 kPa) vacuum to valve port "S". Raise engine speed to 1500 RPM. Air supply should exit outlet "A". If valve does not successfully complete previous testing and air pump is operating properly, replace valve assembly.
NOTE: If valve is of the bleed-type, function and testing is the same. However, a small amount of air will flow from outlet "A" or "B" during tests but main discharge will be switched as stated.
scientia non olet · About LEMON Manuals