Re: 1940 convertible Coupe Issues model 1399

Posted by Owen_Dyneto On 2015/9/3 11:50:39

I know others with similar convertibles will help with your other questions; the vacuum "motor" is the engine itself, it uses manifold vacuum which probably also passes thru a vacuum booster pump incorporated into the fuel pump but when the engine is idling, your solely relying on the engines intake manifold vacuum. An engine in good condition and proper tune should give 18-20 inches of vacuum at sea level, you could check this with a vacuum gauge attached to the intake manifold.

In addition of whatever Packard may have published, older Motor's Manuals have a good section of vacuum convertible top operation and service.