Re: KPack's 1954 Panama

Posted by HH56 On 2022/1/12 12:27:52

Out of curiosity, have you checked the vacuum and is it a good high and steady number? If the manifold line is disconnected and plugged, is the pump doing the job of supplying a reduced amount but still enough vacuum to keep the wipers moving?

The intake manifold port should connect to the pump out port and the wiper motor to the in port. Normal manifold vacuum is strong and will keep the valves wide open during wiper use or a fully closed line will not allow any air to pass so valves should remain still when all is off. Sometimes there is an in between area where the valves in the pump can flutter if an amount of air not adequate to fully pull them open passes thru. The vibration can make a sound and might be what is happening. Have you verified there is absolutely no air flow when the wipers are off -- say maybe due to the wiper valve not closing completely to the motor or the washer port or maybe a loose or cracked hose somewhere.

There are also situations where one of the diaphragms is making the noise either due to misalignment or more likely being pulled tight because the housing screws were tightened while the diaphragm was in a relaxed state rather than having the arm pushed down so as to have the diaphragm pulled out to where it would be at full stroke.