84 Vacuum lines help

[mike231]

I am rebuilding my 84 T and I'm having a problem with my vacuum lines. Before my rebuild I had installed a Bosch boost gauge. This was over 4years ago. At the time I t'ed it into the line coming from the sensor on the fender, or so it seems from looking at the lines now. The aren't connected, but that's what it looks like. I've read several threads for info, but they seem different from what I had/have.
The threads, and the diagrams, show a line from the vac block to the cruise control. The only line on my cruise control (the device on the driver's side next to the charcoal canister??) is a large -3/8 - 1/2" - line that goes thru the firewall to the brake pedal. Nothing to the vac block.
I need some help with the routing. The way it was before worked, but doesn't line up with what I read, and vac diagram.
HELP!

 

[Jerryl]

From a link in the sticky.
Hope this helps.

 

[mike231]

Thanks Jerryl but my problem is that the line from my cruise goes thru the firewall and to a switch on the brake pedal, not to the vac block. And it is fat, like 3/8 or 1/2". Not like the other vac lines. The other question I have is about the vac " box" on the heater motor. One line comes up from under the motor / firewall, goes to the box. The other line is where I am unsure. I think That goes to the vac port on the back of the intake manifold.

I did notice the connection you highlighted says A/C or. Cruise. Where does it hook up to the A/C?
Thanks

 

[Jerryl]

It's been a while so going from memory . . .
The vacuum block has 3 nipples facing the fire wall.
One line (vac source) connects to the cruise control servo at DS front.

One if the other ports on the block is for the vacuum canister at the blower fan, which feeds the AC control head in the dash. The third and last opening connects to a T from the PCV.

The large vacuum line through the fire wall to the switch is correct. This dumps the vacuum at the cruise control servo when applying the brakes.

Extra commentary just in case:
Ensure there are no vacuum leaks at any of the lines and make sure the line from the back if the manifold is secured and leak free *under pressure*.

 

[mike231]

Is there a second line on the cruise servo? I didn't see a second nipple at the servo, just the fat one going to the firewall. If there is, where is it? I'll have to take a closer look tomorrow.
Thanks, mike

 

[Jerryl]

Is there a second line on the cruise servo? I didn't see a second nipple at the servo, just the fat one going to the firewall. If there is, where is it? I'll have to take a closer look tomorrow.
Thanks, mike

Yes, 2 lines to the servo.

 

[mike231]

Can anyone send a close up picture of the cruise servo? I don't see a second nipple, just the fat hose going thru the firewall. Maybe it broke off? I pic would help.

 

[Jerryl]

Just cleaned up some wiring in that area. Hope this helps.



Edit:
Pay no attention to the Y as this is on the 86. Hoses are the same on the HA.

 

[mike231]

Thanks Jerryl. After your last post I went out and took a closer look at the servo. It does have two hose connections, and one was broken off. I couldn't see it without a bright light. By the way if anyone needs a servo, Rockauto has a Cardone brand for $27. Way cheaper than G body or anyone else - $88 and up. It has one of the right PNs for an 84.