I was working on the truck last night installing remote control air bags for the rear end and had to keep the "key on" but not start the vehicle. I noticed the noisy electric motor located on the passenger side firewall just ran and ran, did not shut off in the 5 minute period when I had to have the ignition on.

I am assuming this device is the vacuum pump - am I correct?

Is this device suppose to run and run or is it suppose to build up a vacuum then shut off?

Thanks
SAS

 

suppose to build up a vacuum then shut off, look for a hole in the tubing...

 

Yup. I knocked the "T" right at the back of the valve cover while I was cleaning my engine and snapped the line and had the same issue. That black tubing is too brittle and breaks easy. Find the hole and put some vacuum hose on it and it should fix your issue...

 

I have same problem. I can not find any cracks in the line. Where does the line go to through the firewall? I know all of my a/c heater doors are servo controlled. So what is the vacuum line through the firewall for?

 

Goes to a vacuum reservoir under the cowl, has to be a leak some where...

 

OK will look under cowling in the morning.

 

I did some checking tonignt to find my leak and was able to narrow whether inside the cab or under the driver side batter - issue lies with the line that goes under the battery. I tried finding the leak but could not - looks like I may have to pull the battery and battery tray. What is the negative if I do not find my leak before my run to and from FL? What does this vaccum control / support? Is it just a reservoir under the driver side battery? If that is the case I could just remove the issue from the system. I would not have a reservoir but I would be able to have my pump stop running 100%.
thanks
Scott

 

Cruise control......the reservoir is behind the middle ( so someone told me). I had two cracks in the "hard" plastic line....pump ran all the time......fixed the leaks....solved the problem.....used a stethoscope with a solid copper tube end inserted. NavyDood told me what to look for.

 

Thanks - My cruise does not work, found that out the other day.
What do you mean by reservoir is behind the "middle". From my understanding, the reservoir is under the driver's side battery. Worst case I plug it therefore no cruise which I don't have anyway. Cruise is nice on the flats through indiana, oh well.

Thanks

SAS

 

I would have to look at a manual.......I was told that the reservoir in in the middle of the firewall and behind it.....I have no first hand knowledge of it's location.