vacuum generator question

[ekgflashnet]

My parents 2002 Amabassador vacuum generator runs nearly continously when the vent mode is set to off position.  In any other postion, the vacuum generator runs as expected running when you first start the engine and then stops after a running for a bit.  Would seem to indicate we have a vacuum leak, but I don't understand why the vacuum generator runs when the vent mode is set to off (also when MAX air is set as well).  As a test, I removed the hose coming from the vacuum generator (pump) and put my finger on it.  The pump still had the same issue.  It runs for 20-30 seconds, turns off for 10 seconds or so and repeats the process.  This would seem to indicate to me that the problem is likely in the pump itself since everything else was disconnected at this point.  Any opinions or suggestions.  I inspected all the lines running from the pump to/from the vacuum reservior, but could not see any obvious issues.

 

thanks,

steveg 2005 DDIV

[bobdinsmore]

Hi Steveg,

 

In the past I've had good luck removing the lines from the MAC valve and ]squirting WD40 in the ports. Cleared whatever was fouling up. Nothing to lose to try.

Bob Dinsmore - 2000 Diplomat

 

 

[Ivan K]

Is it an electric generator? If it was air operated, I could do some comparison test. In my experience, vacuum pumps are good at generating vacuum but not so good at holding it when turned off without some sort of a valve which may be a part of the generator or the storage tank depending where the vacuum switch that turns the generator on/off is located.

[ekgflashnet]

It is an electric pump that is creating the vacuum.  Here's a link to the pump.

https://www.amazon.com/Electric-Excursion-Replaces-53032373AA-53032373AB/dp/B07YY11RSG/ref=sr_1_2_sspa?dchild=1&gclid=Cj0KCQjwqfz6BRD8ARIsAIXQCf1eiQoCaC3NI3ye0G0KEYvwvizbeTJxePsg_o5LM4pn8jPKjso-8CgaAoOsEALw_wcB&hvadid=190515408438&hvdev=c&hvlocphy=9030432&hvnetw=g&hvqmt=e&hvrand=1397923548078850883&hvtargid=kwd-301678704445&hydadcr=26612_9479196&keywords=904-214&qid=1600128083&sr=8-2-spons&tag=googhydr-20&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEySzJQODBTSk41VERUJmVuY3J5cHRlZElkPUEwNDAxMzUySEszUjFKWTRIMTNEJmVuY3J5cHRlZEFkSWQ9QTA5NDU4MTcyOE5aV1VWR09NUVdWJndpZGdldE5hbWU9c3BfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ

The vacuum reservior is https://www.amazon.com/s?k=vacuum+reservoir&crid=15KMV0EFIVM5S&sprefix=vacuum+res%2Caps%2C222&ref=nb_sb_ss_i_1_10

I'm going to look on my coach and see if mine is similiar.  I might be able to do some comparison testing.

steveg 2005 DDIV

[trailmug]

The fresh air door is closed only in MAX and OFF positions. Perhaps the fresh air door actuator is leaking?

[ekgflashnet]

good idea.  Where would one go looking for the fresh air door actuator?  Not sure what it might even look like.  Maybe I can try following a vacuum line.

steveg 2005 DDIV