When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I know it’s a pump but does anyone know its purpose?
Anytime the ignition is on, it’s running seemingly full time. From the first moment the key goes to the ON position, it’s working away. What’s it pressurizing or pulling a vacuum for?
No it should not be running full time. It should run, pull a vacuum in the vacuum reservoir ( black plastic thing mounted on the passenger fender well under the hood) then stop.
If it’s running full time you have a vacuum leak somewhere. If your truck is a 4x4, then most likely your auto locking hubs won’t engage. If the vacuum leak is bad enough, you’ll be stuck on defrost and not be able to direct AC to the vents.
…
No it should not be running full time. It should run, pull a vacuum in the vacuum reservoir ( black plastic thing mounted on the passenger fender well under the hood) then stop.
If it’s running full time you have a vacuum leak somewhere. If your truck is a 4x4, then most likely your auto locking hubs won’t engage. If the vacuum leak is bad enough, you’ll be stuck on defrost and not be able to direct AC to the vents.
…
It’s a 2001, 2WD w/ 7.3
The engine runs great. I’ll monitor it over the next few days and see if it ever shuts off.
Maybe it’s a good idea to start replacing vacuum lines. Not being equipped to do my own work, I hope the fix is easy. I could tackle the pump if it needed replacing, a few vacuum lines, but beyond that it’s back to the shop.
Cha-Ching$$$$
Is there an inexpensive and easy way to check for leaks?
It’s a 2001, 2WD w/ 7.3
The engine runs great. I’ll monitor it over the next few days and see if it ever shuts off.
Maybe it’s a good idea to start replacing vacuum lines. Not being equipped to do my own work, I hope the fix is easy. I could tackle the pump if it needed replacing, a few vacuum lines, but beyond that it’s back to the shop.
Cha-Ching$$$$
Is there an inexpensive and easy way to check for leaks?
Block off the two lines and power the truck up. This will give you a starting point. If the pump quits running, then you’ve narrowed your leak down quite considerably. If not then your problem isn’t with either vacuum circuit, but right there under your nose in the engine compartment right there over the passenger side fender.
Is there something you've observed to be not working?
That is what I’m contemplating. I’m a believer in if it works, don’t fix it, however although it seems a bit loud to me, everything works. The only thing that comes to mind is first time starting in the morning, until she warms up a bit, maybe 60-90 seconds acceleration is lacking when I take off for the first time. This only happens when she’s stone cold. Brakes and power steering perform as expected. Once it gets past that first acceleration, she runs strong.
Could there be a relationship between the two characteristics?
Ive never monitored mine but I'm fairly sure it doesn't turn off no matter how long it sits key on engine off and everything works as intended. As far as I know these systems are intended to run non stop providing consistent vacuum just like a gas engine intake does.
One thing is for sure, the vacuum pump has absolutely DIDDLY to do with engine operations. Your truck might feel slow in the cold until it warms up due to the exhaust backpressure valve closing to artificially load the engine and warm it up faster. Or it could be any number of other things.
Mine seems to always be loud on first start of the day, other than then, I don't notice it. I changed to manual hubs and blocked off those vacuum lines at the pump. Oh... and I replaced the pump just a few years ago, so its always been loud...
It’s supposed to turn off once the vacuum reservoir is at the correct vacuum, or at least they all do on my 05 Excursion, my 08 f350 and my 2010 F250 diesel trucks.
…
In the interest of at least attempting to provide the same level of info to the forum that I receive from it, I walked out to my 02 Excursion 7.3 and keyed it on. I stood there for about 90 seconds maybe and the pump did turn off. In this regard I stand corrected.
The only thing that comes to mind is first time starting in the morning, until she warms up a bit, maybe 60-90 seconds acceleration is lacking when I take off for the first time.
This only happens when she’s stone cold. Brakes and power steering perform as expected. Once it gets past that first acceleration, she runs strong.
Could there be a relationship between the two characteristics?
that is normal, I never push my trucks faster than about 20 mph for the first few minutes.
I live next to a major US highway, if it is really cold out, I go around the block the opposite way on 30 mph streets, until things are ready to "hit the road'
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Slideshow: The VelociRaptor Expedition gains a lift, upgraded suspension, Brembo brakes, and trail-ready equipment while retaining the stock 440-horsepower EcoBoost V6.
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.
