Posting this here too, no response from NLOC:

There are two vacuum reservoirs attached attached to the rear of the battery tray. I know one is for the hvac controls. Not sure what the other one is for - EGR?

Has anyone deleted this box, i.e. capped both lines going to it, and not had problems? My search only pulled up one thread, which indicated some funky a/c behavior at WOT. Otherwise, are there any detrimental effects too deleting the box completely?

 

HI!... I deleted the black box a few years ago. I only had one large one. It had one line running in and one line running out. All I did was remove the box and join the two vacuum lines together. The only thing that happened as a result of doing this is that I can't control the heater controls when the truck is not running. Like who cares, why would I want to anyway? LOL! I deleted my A/C as well so I did not notice anything with that.

Your talking about this right?

 

Yep, that's it. On my '04, it's actually two boxes clipped together. One line on top, one on the bottom. I'm doing a battery relocation, and there's nowhere convenient to locate this thing. I was thinking about joining the lines together too and tucking them out of the way. Good to know it can be done. Thanks Neal!

 

I believe the other box stores the vacuum used to activate the boost dump feature for the blower.

 

that black box that Neal has a pic of is the air conditioner vaccum resevoir

duh he already said that

 

Sal, it sounds like you may think it's a bad idea to delete that. Am I right?

 

Well, I guess look at it this way... If you've got a boost bypass "mod kit" or you have the boost dump turned off in your tune, then I guess it's really a mute point. I have never removed that box, so I'd just try disconnecting it first, and see if the bypass still works properly.

 

Along the same lines. For those that have switched to an Optima and removed the factory batter tray (which the black box connects to) What did you do with the box. I wedged mine in but after a few hundred miles it'll start vibrating. I like the idea of deleting it if that is ok.

 

I mounted mine with velcro.
It worked fine.
I moved the battery to the bed and installed a Powercooler, the vac box fits right between the cooler and the firewall.

 

I strapped mine against the fender with a 1 inch by 15 inch or so piece of aluminum

https://www.f150online.com/galleries...8130&anum=1108