Re: 54 Patty vacuum lines

Posted by HH56 On 2015/3/13 12:44:31

And doing Owen's explanation one step more as to why the pump operates when it does, the vacuum pump has valves constructed in such a way that under normal operation and high manifold vacuum conditions, just makes the pump act like another length of tubing for the vacuum going to wipers. Only when manifold vacuum drops or is completely absent do the springs operating the valves have enough strength to close the valves so pump can start to work.