Ok, I was drinking a beer and looking at the truck in the garage. I know, I have a problem, with looking at the truck too much. Any who, I decided to open the drivers door and press the brake pedal and check the brake lights by looking at them shine on the garage door. Well....something started to run, at first I thought it was a fuel pump, but then I check and it was under the hood. The pump/whine noise lasted for a few minutes, long enought... that I thought I was going to have to start the truck to make it stop. I even locked the doors and unlocked to see if that would make it stop, that didn't make a difference. The key was never in the truck when this happen.

Any ideas what the heck that was running under the hood ?

 

The brakes are vacuum assisted, so my best guess would be some kind of vacuum pump. The pump might be setup to run totally independent of the engine running or the key being on. That way, if one of those interconnected parts fail, you can still stop the truck, even with a heavy trailer.

 

If you do it again check the ABS unit and see if it's running or just have another beer and not worry about it.

Denny

 

Were going to need more information from you to diagnose the problem. Like, how many beers did you consume before observing this phenomena? At what rate did you consume the beers? What kind of beer was it? Import or domestic? Did you drink the beers while on medication? What temperature was the beer when you chugged it?

 

Nothing good ever comes of me drinking beer and staring at my truck. That's usually the point when I realize it's time for another mod...

I just went out and tried it on my truck and nothing continued to run. There's so many nannies on these trucks, it doesn't surprise me though. Is it anything like the noise in this video?
https://www.ford-trucks.com/forums/1...l#post13084960

If so, I found your problem, you have a diesel.

There was a TSB out there for it that was related to the vacuum pump, but it also included a comment regarding the waste gate, which we obviously don't have. I'm going with the others and saying it's the pump..

Quote:

22508 ; 2011-2012 6.7L PICK UP TRUCK - BUZZING UNDER HOOD AFTER SHUTDOWN
SOME 2011-2012 F250-450 SUPER DUTY PICKUP TRUCKS EQUIPPED WITH A 6.7L DIESEL ENGINE MAY EXHIBIT A BUZZING NOISE FROM UNDER THE HOOD AFTER THE ENGINE IS SHUT OFF. THE BUZZING NOISE IS CAUSED BY NORMAL VACUUM BLEED OFF IN THE VACUUM SYSTEM RESULTING IN THE WASTE-GATE SOLENOID BUZZING. THIS NOISE NORMALLY LASTS FOR APPROXIMATELY 30 SECONDS. ENGINEERING HAS REVIEWED RETURNED COMPONENTS AND DETERMINED THIS IS A NORMAL VEHICLE CHARACTERISTIC. DO NOT ATTEMPT TO REPAIR THIS NOISE. CHASSIS CAB VEHICLES DO NOT APPLY TO THIS ARTICLE BECAUSE THEY ARE NOT EQUIPPED WITH WASTE-GATE.
EFFECTIVE DATE: 08-SEPTEMBER-2012

 

Very funny! Miller lite and on # 2 and it was cold.

 

Thanks, I did pump the pedal a couple of times and it did seem to get hard. Vac pump, even though I never heard of one,
I always though it used the engine vac. that could be it. It was much too quite for an ABS pump.

Thats it... sounds like the noise in the video.

Go out and try it again, pump the pedal a couple of times.

Vac pump so you have full brakes if the engine quits?

 

I had the same thing happen to me while installing my cb, I was laying on the floor and running wires through the dash and heard something run, I turned the key on and then off and it stopped? I tried wiggling wires but could not get it to do it again, I will have to try the brake pedal, truck was parked a couple days so maybee it doesn't happen if there is pressure left if its run every day, or once its pumped back up? I only get to drive mine once a month or so now that its broke in enough to tow. 111 miles round trip for work means to expensive for that.

P.S. I was on my third sierra nevada torpedo when it happend to me

 

Mine does the same thing. A couple months ago I sat in my truck to sink up my new phone and as soon as I hit the brake pedal I heard the noise (and I was sober). I figured it was a fuel pump. Good to hear it has to do with the brakes.
Mystery solved!

 

I have heard a buzzing from the engine compartment after opening and closing the door. Never thought anything of it, never had a problem with the truck and everything works perfect on it, just thought it was normal.

 

Mine does it all the time. Nothing to do with the break pedal. If the key is in the ignition (off position) and I open the door it starts and continues for at least 5 minutes. I've had two professional wrenchs listen to it, still don't have a clue! Everything works just fine, so no worries!

 

Mine only does it if I hit the break pedel.