Check Valve No. 2 Installed Backwards

Same as with leaking valve. Also, with cold engine, blower will not shut off when "OFF" button is pushed.

Test check valves as follows:

1. Connect a vacuum gauge and source vacuum to check valve (see illustration).
2. Note gauge reading, then remove vacuum supply hose. Gauge reading should remain the same. If gauge reading drops off, replace check valve,
   CAUTION: Do not use any fluid or lubricant on check valves in an attempt to improve their efficiency. Damage to vacuum system may result.