How does the changeover valve on a Mercedes Benz work?
When the solenoid is energized its valve opens, applying vacuum to the vacuum diaphragm pot, which in turn operates the external lever causing the switchover vanes to close. Once the solenoid is de-energized, a spring inside the vacuum diaphragm forces the vanes back to their open position.
Where does the 2 Y connector go in a vacuum?
It seems to me that in the 2-Y connector setup , the #2 prong (of the Y connector) as I’ve labeled it goes to the change over valve, the #1 to the vacuum reservoir, #3 to the check valve, # 4 to a non return valve (I’ve deduced where #4 goes based on the routing diagram/flowchart (not the illustration).
How to test the vacuum diaphragm and hose?
One way to test the vacuum diaphragm and hose is to disconnect its hose from the solenoid, manually rotate the external linkage counter-clockwise to its fully engaged position, place your finger over the end of the hose to seal it off then release the external linkage. The linkage should move about half way back to its resting position then stay.
When the solenoid is energized its valve opens, applying vacuum to the vacuum diaphragm pot, which in turn operates the external lever causing the switchover vanes to close. Once the solenoid is de-energized, a spring inside the vacuum diaphragm forces the vanes back to their open position.
It seems to me that in the 2-Y connector setup , the #2 prong (of the Y connector) as I’ve labeled it goes to the change over valve, the #1 to the vacuum reservoir, #3 to the check valve, # 4 to a non return valve (I’ve deduced where #4 goes based on the routing diagram/flowchart (not the illustration).
One way to test the vacuum diaphragm and hose is to disconnect its hose from the solenoid, manually rotate the external linkage counter-clockwise to its fully engaged position, place your finger over the end of the hose to seal it off then release the external linkage. The linkage should move about half way back to its resting position then stay.