Hi all,

There is what seems to be a vacuum pump on the right front fender of my Excursion that runs for an extended period of time when the truck is switched "on" after a bit of time off (overnight). It runs for a bit (60 seconds) before cutting off. I don't remember that from my first Excursion.

Is that the cruise control pump? Is there a leak somewhere?

Chris

 

You must have a diesel, huh? Since the diesel has a turbo, it doesn't create vacuum. But vacuum is necessary to operate the blend door on the heater, and the hubs for a 4wd. Hence the little vacuum pump and reservoir.

 

yes, deezles have a vac pump that comes on when u first turn on the key.... I don't recall mine staying on after key off though.... no ned for vacum then

I did think I had a pump running in the rear of my 05 Ex that I never heard on the 02 or 03...

isolated it to the rear entertainment center !!!
a 'fan' in the unit stays on all the time... heard easily when the engine and radio is off...
but if I change the radio to cd and then go back to radio, it cycles off until the next restart....

When new, Svc advisor told me it was to keep the unit cool

I didn't buy that, but it doesn't bother me enough to worry about it...

 

It'll stay on till theres the perfect amount of vacuum in the system.. if theres a leak in a line or hub.. then it will run constantly.

The switch beside it is a perfect candidate of losing vacuum.