I have a 79 cab with A/C and a 460. . I am trying to hook up vacuum lines. I think one goes from firewall by drivers side to canister under drivers fender. Them maybe to heater box?

I have searched and searched but found nothing to help me. All my egr, etc has been removed.

 

I need this info, too.

 

A '79 has a 3-port check valve external to the reservoir (canister). Manifold vacuum, canister, and heater controls all connect to the check valve. You'll also have a lone (small I/D) vacuum line coming from the firewall that goes out to the heater core shutoff valve.

 

Most people are unaware that there were three different types of A/C for these trucks. Factory and two different types of Ford dealer installed.

No vacuum reservoir (mounted on left fender inner apron), no vacuum controlled heater water valve (spliced into heater hose) unless the truck has factory installed integral A/C or Hi/Lo Comfort Vent System.

Factory installed integral A/C combined with the heater, the A/C controls are located in the same panel as the heater controls.

 

It has factory a/c. Is there a link to a picture of the routing. I have nothing to go by and i'm 150 miles from my computer.

The truck was stripped to the frame and just trying to get heater vacuum hoses routed properly. Thanks.

 

Lol. Make that a 3rd that's having fun with the ac Vacume lines.

 

I have a 77 F150 with factory AC with the vacuum canister mounted to the Battery box that is not currently connected. Does this have that 3 way valve your talking about? Do you have a part number? OP, sorry for the hijack

 

D6TZ-19A566-A .. A/C Vacuum Reservoir Tank & Bracket / Use with factory installed integral A/C or Hi/Lo Comfort Vent System (F100/350) / Marked: D6TA-19A566-A / Obsolete

Applications: 1976/77 F100/350 & Econoline / 1978 F100/350, Bronco & Econoline before serial number AJ0,001.

NOS PARTS LTD in Waxahachie TX has 2 = 972-937-2201.

 

The vacuum reservoir by the battery is part of the emission control system. The reservoir for the A/C is a small metal can (73-75) or plastic "ball" (76-79) mounted on the driver's side splash pan.
Early models had three lines that pass through the firewall, later models had two.
There is a vacuum line that goes from the manifold vacuum tree to the vacuum reservoir. Then, the larger diameter line goes from the firewall to the reservoir. The one or two small diameter lines go to the heater water shut off valve located in one of the heater hoses. Early models had two vacuum lines, later models had a single line.
Here's the illustration from the Ford parts catalog, click on the .pdf link.

 

That helps part of my Vacume issues. Lol. Now which vac live goes to which dohicky down under the dash on the inside of the cab?

 

Under the dash it should be pretty much foolproof. The lines are color coded and go into molded plugs. The plugs only go on one way.
Not sure if the 79 is the same but the pics are of a '76.
The vacuum line goes from the vacuum reservoir through the firewall. It then T's off and goes to both plugs. On the three line plug it's brown, green, black (black is the vacuum line). On the seven line plug, the vacuum line (black) is located between the yellow and green line.

 

Also, the other line that goes through the firewall, the one that goes to the water shut off valve is the one with the brown stripe and goes to the three line plug.

 

Crap guy's, I'll have to wait until this weekend to figure this out. I have the ball on the left inner fender and the juice can on the battery bracket. I'm sue one was added by me in the past just because...LOL

Thanks for all the info....