LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Subaru >> 1985 >> XT DL >> Repair and Diagnosis >> Engine Performance >> System >> EGR Function Testing >> Component Testing >> THERMO Vacuum Valve >> Carbureted Vehicles
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Carbureted Vehicles

  1. Remove valve from intake manifold. Connect hoses to the output ports for air cleaner and EGR valve (2 upper ports) and plug output port to canister (1 lower port). See Fig 1 . Submerge valve into a container of cold water.
    NOTE: DO NOT allow water to enter valve.
    NOTE: When inspecting vacuum valves, ensure proper operation occurs at specified temperatures.
    Fig 1: Sectional View of Thermo Vacuum Valve and Check Valve
    G38183
  2. Heat slowly to raise temperature of water. Blow air into valve and confirm that the valve opens or closes in response to water temperature.
  3. Thermo vacuum valve should completely open below 86°F (30°C) and should completely close above 104°F (40°C). Remove thermo valve from water. Connect vinyl tubes to output ports to EGR valve and canister, and plug output port to air cleaner with a cap.
  4. Blow air into valve and confirm that valve opens and closes in response to water temperature. Valve should completely open below 86°F (30°C) and should completely close above 104°F (40°C).
scientia non olet · About LEMON Manuals