LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Nissan-Datsun >> 1971 >> 1000 >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Air Injection Pump >> Testing >> Check Valve
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Check Valve

  1. Make sure that the valve plate inside valve body is lightly positioned against valve seat, away from the air distributor manifold.
  2. Insert a probe into the valve connection on the check valve and depress valve plate. It should return freely to the original position, against valve seat, when released.
  3. Leave hose disconnected and start engine. Slowly increase engine speed to 1500 RPM and look for exhaust gas leaks at the check valve. The valve may flutter or vibrate at idle speed, but there should not be any exhaust leakage. If check valve does not operate properly, replace valve.
    Fig 1: AIR PUMP SCHEMATIC
    G09355058Courtesy of NISSAN NORTH AMERICA, INC.
scientia non olet · About LEMON Manuals