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Gasoline System Testing: THERMOVALVE

  1. If vacuum does not drop to 10 in. Hg, disconnect vacuum lines from thermovalve. Connect vacuum tester to angular connector of thermovalve and apply vacuum. If coolant temperature is above (50°C) valve should be open. If coolant temperature is below (50°C) valve should be closed. Replace thermovalve if not operating correctly.
  2. If valve is operating, check for leaks. Disconnect both vacuum lines from thermovalve. Seal the straight connection and apply vacuum to angular connection. If vacuum is retained valve is okay. If valve will not hold vacuum, replace valve.
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